7,1'p LECTURES ON M I N E R A L O G Y. DELIVERED AT THE SCHOOL OF I NE-S, COLUMBIA COLLEGE. DESCRIPTIVE MINERALOGY. BY T''EGLESTON, Profes-sor of MillSe'alogy adllcl Aetallli.g ry, School of MlcEs, Columbia Co71ege WITH 34 LITHOGIRAPHIC PLATES. NEW YORK: D. VAN NOSTRAND, PUBLISHIER, 23 MURRAY AND 27 WVARE3N STREET. 1872. Entered, according to Act of Congress, in the year 1871, by THOMAS EGLESTON, JR., In the Office of the Librarian of Congress at Washington. ERRATA. Page xviii and xxvi. The note t does not apply to the plates of this edition. xxiv. If the brachy axis is placed in front, the formulae for the macro and brachy domes are right. If the macro axis is placed in front, the formulm should read m'P'oo, mn,P,co and m,P'oo,m'Poo. 11. 14th line from bottom, Florentine should read Florentine (yellow.) 21. 11th line from bottom, for Borax read SPh. 27. 2d line from bottom, for Borax and SPh. read Fluor and f_ 12. 49. 15th line from top, for Na GCa read (,a Ta. 54. 14th line from bottom, for Ryacolite read Rhyacolite. 66. 14th line from bottom, for or read and. 83. 8th line from top, for red read reducing. 87. 21st line from bottom, for red read reducing. 92. 18th line from top, for base read hemi-pyranmid. 92. 21st line from top, for P read -P. 92. 22d line from top, for -P read P. 92. 23cl line from top, for obtuse read acute. 102. 16th line from bottom, for R read — R. 103. 21st line from botto-m, for with nitrate of Cobalt read by fusion with Soda. 121. 4th line from bottom, for flame of a candle read R. F. on coal. 127. 20th line fiom top, for globule rea(l powder. 134. 6th line from bottom, for Chromiumll read Manganese. 189. 13th line from top, for orange colored read white. 139. 14th line from top, for AsS read;is. 144. 25th line from top, omit borax. For O. F. read R. F. 161. 25th line from top, for copper read baryta. PREFACE. THESE lectures are what their title indicates, the lectures on Mineralogy delivered at the School of Mines of Columbia College. They have been printed for the students, in order that more time might be given to the various methods of examining and determining minerals. The second part. only has been printed. The first part, comprising crystallography and physical mineralogy, will be printed at some future time. Only those species have been described with which it is necessary for an Engineer of Mines to be familiar, or which present some peculiarity of interest. The list of synonyms is -not complete;. only the most familiar names used in Germany, France and the United States have been given. The lecture notes were written out somewhat hastily, amid the press of other duties, but it is hoped, that as they occupy a ground not hitherto entirely covered by other elementary works, they may prove acceptable to students wishing to commence the study of Mineralogy. As it has already proved serviceable at the School of Mines, it is hoped that it may be found useful elsewhere. As it is quite essential that the notation of both Naumann and Dana should be understood, the first has been adopted in the text and the second used on the faces of the crystals. A table giving the comparison of the principal notations in use, has been given in the introduction. In the preparation of the work I have been greatly indebted to my assistant, Mr. J. H. Caswell, who autographed the drawings and prepared the notations of the faces of the crystals. T. EGLESTON. SCHOOL OF MINEs, 1871. CONTENTS. Page Classification of the Species according to Crystalline Form, viii Do do Hardness, x Do do Specific Gravity, xii Systems of Crystallization, xv Names used by different Authors, xv Scale of Hardness, xv Comparison of Notations used to represent the Faces of Crystals, xvi DESCRIPTIVE IMINERALOGY-SYSTEMATIC CLASSIFICATION OF SPECIES. Hydrogen. II. Unisilicates. Feldspar Grou2. Water... I Chrysolite Group. Anorthite,.. 50 Sulphur. Chrvsolite, 33 Labradorite,. 51 Sulphur,... 5 Jhenacite G Oligoclase,. 51 Tellurium. Willemite,. 34 Albite, 52 Tellurium, 7 Phenacite,. 35 Orthoclase,. 53 Calrbon.' ar~wt Groul). III. Subsilicates. Diamond,. 8 Garnet Group. 5 Chondrodite,. 59 Graphite,... 13 arnet,.. Tourmaline, 60 Carbonic Acid, 14 Vesuvicnite Gr'oup. Andalusite,. 61 EBor>on. ] Zircon, 38 Fibrolite,.3 Fibrolite.. 63 Sassolite,.. 14 Vesuvianite.. 39 Cyanit.. 6 silicon. E2pidote Gr~oup. Topaz,... 64 Oxygen Compounds. Epidote,... 40 Euclase,.. 65 Quartz,.. 14 Iolite Groulp. Datolite, 66 Opal, 20 Iolite,.. 42 Titanite, 67 $L][CAJTES.. Mica Grou2p. Staurolite,. 68 ANHYDROUS SILICATES. Biotite,... YDROUS SILICATES. I. Bisilicates. Muscovite, 44 I. Bisilicates. Amnphibole Group. Lepidolite,.. 45 Pectolite Group. Wollastonite, 21 Scapgolite Group. Pectolite,... 68 Pyroxene,... 22 Wernerite,.. 45 Laumontite,. 69 Rhodonite,.. 26 Nephelite Group. Dioptase Group. Spodumene,.. 27 Nephelite,.. 46 Dioptase,.. 69 Petalite,.. 27 Leucite Grouplf. Chrysocolla,.. 70 Amphibole,.. 28 Lapis Lazuli,. 47 II. Unisilicates. Beryl Grou2p. Hauynite,.. 48 Cclamine Grou2p. Beryl,.... 32 Leucite,... 48 Calamine,... 70 vi CONTENTS. Prehnite,... 71 Apatite,.. 95 Pyrolusite,. 131 Chlorastrolite, 72 Pharmacolite,. 96 Manganite,.. 132 Apophyllite Group. Aragonite,.. 96 Psilomelane,.. 132 Apophyllite,.. 72 Calcite, 98 Wad,. 133 ZEOLITE SECTION. Dolomite,.. 102 Alabandite,. 134 I. Unisilicates. Scheelite,... 104 Triplite,. 134 Natrolite,.. 74 M9agnesium. Rhodochrosite, 135 II. Bisilicates, 75 Brucite,. 105 Cobalt. Analcite,. ~ 75 Epsomite L te Chabazite,~. 76 Epsomite,. 105 inate,. 135 Chabazite,. 76 Boracite, 106 Bieberite,.. 136 Harmotome, ~ ~ 76 Magnesite,. 106 Smaltite,. 136 Stilbite, 77 Spinel,... 107 Cobaltite,... 1386 Heulandite, ~. 78 Aluminium. Erythrite,.. 137 I. Bisilicates.'sR(;apOPj~i~~~.IrCorundum,.. 108 Remingtonite, 137 Tale Group. Diaspore,... 109 ickel. Talc,.. 79 Aluminite,. 110 Millerite,... 138 Sepiolite Group. Alunogen,. 110 Niccolite,.. 138 Sepiolite,... 80 Alunite,. i Ullmannite,. 139 II. Unisilicates. Kalinite,... 111 Annabergite, 139 Serpentine Group. Cryolite,. 112 Zaratite,. 139 Serpentine,.. 80 Turquois, 112 Zinc, lII. Subsilicates. Wavellite,. 113 Zincite,... 139 Chlorite Group. Chrysoberyl,. 113 Sphalerite,. 140 ~Prochlorite,.. 81 Ifron. Goslarite,... 141 Potassium. Iron,... 114 Smithsonite,. 141 Nitre,.. 82 Magnetite,.. 115 Hydrozincite,. 142 Aphthitalite,. 82 Franklinite,. 11 Tin. Sodliumn. Hematite,j. 117 Cassiterite,. 142 Soda Nitre,.. 83 Goethite,.. 118 Stannite,... 143 Thenardite,.. 83 Limonite,.. 119 Titanium. Mirabilite,.. 83 Pyrrhotite,. 120 Rutile,.144 Glauberite,.. 84 Pyrite,.. 121 Octahedrite, 145 Halite,.... 8.4 Marcasite,. 123 Brookite,. 145 Borax,.... 85 Melanterite,. 123 Lead. Natron,... 86 Copiapite,. 124 Lead,.... 146 Ammonium. Vivianite,... 124 Minium,... 146 Mascagnite,.. 86 Leucopyrite,. 125 Galenite,... 146 Sal Ammoniac,. 86 Arsenopyrite,. 125 Bournonite,. 148 Barium. Scorodite,. 126 Anglesite,.- 149 Barite,.... 87 Pharmacosiderite, 126 Clausthalite,. 149 Witherite,.. 88 Arseniosiderite, 127 Pyromorphite. 150 Barytocalcite, 89 Siderite,. 127 Mimetite,...151 Strontium. Menaccanite,. 128 Cerussite,.. 152 Celestite,... 89 Chromite,. 128 Crocoite,.. 153 Strontianite,.. 90 Columbite,.. 129 Stolzite,... 153 Calcium. Wolframite,. 129 Wulfenite,.. 153 Anhydrite,.. 91 Manganese. Bismuth. Gypsum,... 92 Braunite,... 130 Bismuth,... 154 Fluorite,... 94 Hausmannite,. 130 Bismuthinite,. 155 CONTENTS. vii Aikinite,.. 155 Copper. Calomel,... 172 Tetradymite, 156 Copper,... 163 Silver. Arsenic. Cuprite,... 163 Silver,.... 173 Arsenic,... 156 Chalcocite,.. 164 Amalgam,.. 173 Arsenolite,.. 156 Bornite,. 165 Argentite,.. 174 Realgar,... 157 Chalcopyrite,. 165 Proustite,... 175 Orpiment, 157 Tennantite,.. 166 Pyrargyrite,.. 175 Antimony. Tetrahedrite, 167 Stephanite,.. 176 Antimony,.. 158 Chalcanthite,. 167 Polybasite,.. 176 Senarmontite,. 158 Brochantite,.. 168 Cerargyrite,.. 177 Valentinite,.. 159 Atacamite,.. 168 Bromyrite,.. 177 Stibnite,... 160 Libethenite,. 169 Embolite,... 177 Kermesite,.. 160 Olivenite,.. 169 Iodyrite,... 178 UTranium. Liroconite,.. 169 Gold. Uraninite,.. 161 Malachite,.. 170 Gold,.... 178 Autunite,... 161 Azurite,.. 171 Platinum. Torbernite,.. 162 Mercury. Platinum,.. 179 Molybdenum. Mercury,... 171 iridiunm. Molybdite,.. 162 Cinnabar,. 172 Iridosmine,.. 180 Molybdenite, 162 CLASSIFICATION OF THE SPECIES ACCORDING TO CRYSTALLINE FORM. ISOMETRIC. I)iamond, Kalinite, Ullmannite, Tennantite, Garnet, Iron, Sphalerite, Tetrahedrite, Lapis Lazuli, Magnetite, Lead, Mercury, Hauynite, Franklinite, Galenite, Silver, Leucite, Pyrite, Clausthalite, Amalgam, Analcite, Pharmacosiderite, Arsenolite, Argentite, Halite, Chromite, Senarmontite, Cerargyrite, Sal Ammoniac, Alabandite, Uraninite, Bromyrite, Fluorite, LinnTeite, Copper, Embolite, Bracite, Smaltite, Cuprite, Gold, Spinel, Cobaltite, Bornite, Platinum. TETRAG ON A L. Zircon, Scheelite, Stannite, Wulfenite, Vesuvianite, Braunite, Rutile, Torbernite, Wernerite, Hausmannite, Octahedrite, Chalcopyrite, Apophyllite, Cassiterite, Stolzite, Calomel. ORT H OR HII OMBIC. Sulphur, Staurolite, Aphthitalite, Aragonite, Chrysolite, Calamine, Thenardite, Epsomite, Iolite, Prehnite, Mascagnite, Diaspore, Muscovite, Natrolite, Barite, Wavellite, Lepidolite, Stilbite, Witherite, Chrysoberyl, Chondrodite, Talc, Celestite, Goethite. Andalusite, Serpentine, Strontianite, Marcasite, Topaz, Nitre, Anhydrite, Leucopyrite, Viii ix Arsenopyrite, Goslarite, Orpiment, Brochantite, Scorodite, Brookite, Valentinite, Atacamite, Columbite, Bournonite, Stibnite, Libethenite, Wolframite, Anglesite, Autunite, Olivenite, Pyrolusite, Cerussite, Molybdite, Stephanite, Manganite, Bismuthinite, Chalcosite, Polybasite. Triplite, Aikenite, MONO CLINIC. Wollastonite, Datolite, Natron, Erythrite, Pyroxene, Titanite, Barytocalcite, Annabergite, Spodumene, Pectolite, Gypsum, Crocoite, Petalite, Laumontite, Pharmacolite, Realgar, Amphibole, Harmotome, Alunogen, Kermesite, Epidote, Heulandite, Melanterite, Liroconite. Orthoclase, Glauberite, Vivianite, Malachite, Fibrolite, Mirabilite, Bieberite, Azurite. Euclase, Borax, T R ICLIN IC. Sassolite, Labradorite, Albite, Cryolite, Rhodonite, Oligoclase, Cyanite, Chalcanthite. Anorthite, HEXAGONA L. Water, Chabazite, Pyrrhotite, Bismuth, Tellurium, Prochlorite, Copiapite, Tetradymite, Graphite, Soda Nitre, Siderite, Arsenic, Quartz, Apatite, Menaccanite, Antimony, Beryl, Calcite, Rhodochrosite, Molybdenite, Willemite, Dolomite, Millerite, Cinnabar, Phenacite, Brucite, Niccolite, Proustite, Biotite, Magnesite, Zincite, Pyrargyrite, Nephelite, Corundum, Smithsonite, Iodyrite, Tourmaline, Alunite, Pyromorphite, Iridosmine. Dioptase, Hematite, Mimetite, AMO RPH O US. Carbonic Acid, Sepiolite, Arseniosiderite, Zaratite, Opal, Aluminite, Psilomelane, Hydrozincite, Chrysocolla, Turquois, Wad, Minium. Chlorastrolite, Limonite, Remingtonite, CLASSIFICATION OF THE SPECIES ACCORDING TO HAR DN E S S. Xl[. < 1 H.=1L5=2 Pyrargyrite, M.=-' 5-35 Carbonic Acid, Alunogen, Pyrousarite, Senarmontite, Mercury, Gypsum, Steplalnite, Calcite. Molybdite, Mirabilite, Telluriun, Sassolite, Orpiment, Tellurium, ] I.=flt7'2'9 Water. Realgar,'7, Water. Sal-Ammoniac Torbernite. Biotite. EH. -=0'5-6 Soda-Nitre,.2-3 H.-2 7-3 Wad. Tetradymite, Vivianite. Chrysocolla, Anglesite, Kalinite, Wulfenite. = I.=1' 5 — 2'5 Lepidolite, Cerargyrite, Erythrite. Minium, H.=2 75 —3 Embolite, Polybasite. Stolzite. Todyrite, Il.=2 Kermesite,.=' Molybdenite, Melanterite, Chalcanthite. Natron, Nitre, Bornite, Talc. Stibnite. Halite, Olivenite,-. Muscovite,. Serpentine. Pharmacosiderite, Aluminlite,:Epsomite. Sepiolite..-3 —3 Arseniosiderite, H.=2-2.7 Zaratite. Calomnel, Aikinite, Galenite.. =3 -3*5 Argentite, Graphite. Autunite, Amalgam, H.ra 2i.6 Bismuth, Anhydrite, Bismuthinite, Annabergite, Antimony, Sulphur. Borax, Bournonite, Aphthitalite, Cinnabar, Chalcocite, Atacamite, H..=1'5 Goslarite, Clausthalite, Celestite, Hydrozincite, Copper, Cerussite, Arsenolite, Liroconite, Crocoite, Millerite. Brucite, Mascagnite, Glauberite, Copiapite, Pharmacolite, Gold, H[.=3-4'5 Ice Prochlorite, Silver, Lead. Proustite, Valentinite. Tetrahedrite. x xi H. =32 —4 H.-4- -45 H.-5-6'5 Iridosmine, Prehlnite. WVavellite. Chabazite, Hematite. Prehnite Chabazite, Platinum, Epidote, HE. =3'5 Zincite. H.- Epidote, Analcite, Vesuvianite. Arsenic, 1.-4 —5 Chromite, Laumontite, Cobaltite, Mimetite. Pectolite. Datolite, Chrysolite, Lapis Lazuli, Diaspore, B11. ~=3W5-37 1s~ BfH.=415 LiUnmeite, Garnet, Uraninite, Spodumene. VWitherite. Iron, oWillemite. Iarmotolue. H.="H 3 —4'~~ 1451t.=3'5 —6 Boracite,.=3,541 11.=45 —5 uartz. Arsenopyrite, Alabandite Apatite, Brookite, Aragolunite, Apophyllite, Chlorastrolite, Aragonite Scheite, Haiynite, Iolite,:Brochantite, Wollastonite. Leucite, Staurolite, Chalcopyrite, ZMagnetite, Tourmaline., Cuprite, -f1=5 Nephelite, Dolomite, Octahedrite, B.7*5 Maeulachite, Calamine, Smaltite. Andalusite, alachite, Chromite, Euclase, Pyromorphite, Dioptase,.-Zircone, Scorodite, Franklinite, Opal, Sphalerite, Smithsonite. Rhodonite. 1f.=7?5-S8 Stilbite, Strontianite, IE —5 I.=J Beryl, Tennantite. t Phenacite. Anorthitc, Goethite, Columbite, ~HI. -34 *=4L2 GHausmannite, Labradorite, Leucopyrite, Oligoclase, Spinel, Limonite, Orthoclase, Topaz. Azurite. Natrolite, Turquois. Niccolite, _. -=8'5 a Titanesitnite,. Chrysoberyl. Magnesite, Triplite, Pyrrhotite, Ullmannite, Albite, Rhodochrosite, Wolframite. Braunite, 1.=9 Siderite. Chondrodite, Corundum. Hj.=5-6 AMarCasite, [H.=4 Petalite, ].=10 Amphibole, Pyrite, Barytocalcite, Cyanite, Rutile. Diamond. Fluorite, Menaccanite Libethenite, Psilomelane, Manganite, Pyroxene, Cassiterite, Bieberite, Stannite. Wernerite. Fibrolite, Remingtonite. CLASSIFICATION OF THE SPECIES ACCORDING TO SPECIFIC GRAVITY. G.=0'91S-1 G.=1'9 —2'3 G.=235 —2'39 Oligoclase, Water. Opal. Apophyllite. Pharmacolite, Wernerite. G.=1,2 —1'6 G.=2 GG.=2'4 G.=26 2S Sepiolite. Graphite. ilarmotome. Glauberite, G.-=1 4 G.=2 —2'1 Gz.=2'4l-2' 5 Prochlorite, Mirabilite, Chabazite. Leucite. Talc, Natron. G.=2-22 G.Turquois. G. = 1'4S~ Chrysocolla, laiiynite. Sassolite. Soda-Nitre, G.=2*42-24 Phenacte. G. =.5 Stilbite. Petalite. G.= 2e7 Carbonic Acid G.=2-25 G.=2.47-2 Thenardite. Sal-Ammoniac. Biotite. Serpentine. G.=2'7-2S8 G.=1'5 —1'$ G.=2'072 G.=2'5 — 26 Pectolite. Kalinite. Sulphur. Iolite, G.=27 —2' 9 G.-1@6 G.=2'1-262 Nephelite, Wollastonite. Aluminite. ZHeulandite Zaratite. Aluminite. INatrolite. G.=2 5-27 G.=2'3 — 9 G.=F6 — 1S G.=116-. 5 Alunite, Anhydrite, Alunite, Dolomite, Alunogen. Halite. Calcite, Liroconite, G.=I'?7 G.=282 Quartz. Prehnite. Aphthitalite, Analcite, G.=25'53-2*' 9 G.=2*'-3 Borax, Chalcanthite. Orthoclase. Datolite Datolite, Epsomite, 2G.=2'2 —2' 411 G.-2__54,2'64 Lepidolite, Mascagnite. Laumontite. Albite. Magnesite. G.=F'8 G-s3 G.=2 G.= 6 G.=2'S-3-1 Helanterite. Brucite, Vivianite. Mluscovite. G.=1'9 Gypsum, G.=-6-ev7 G.= 9 Nitre. Wavellite. Anorthite, Aragonite, B.-*9-2 G.=2~eryl, Boracite, Goslarite. Lapis Lazuli. Labradorite, Erythrite. xii xiii G.=29 —3 G. 3-35-3-5 G.=3'7-4'3 G.=4*3-4'5 CPhryolite, Calamine. Psilomelane. Chromite, Pharmacosiderite. G.-=3'4 G.=3'S -39 Stannite. Amphibole. Orpiment. Brochantite, G. =4l4-4'7 GP.=- G=3~4 -3~6 Octahedrite. Pyrrhotite. Annabergite, Realgar,.=3-4 Autunite, Rhodonite, Willemite. Molybdenite. Euclase. Rhodoclrosite. G 39 G.= - G. = 3-3~2 G. =304-308 Celestite. Bornite. Tourmaline. Staurolite, G.=3*9 —4 G. =45-46 G.=3'1 Triplite. Alabandite, Kermesite Chondrodite, G.=3'5 Corundum, Stibnite. Fluorite. Arseniosiderite Sphalerite. G.=4L5 - G. =31 —3.2 Topaz. G. = 4-43 Meaccanite. Andalusite, G. =3'5 36 Atacamite. Spodumene. G.=45 —5'1 G.=3o1-3.3 |Cynite, G=4-~4 Tetrahedrite. Scorodite. Hydrozincite, Goethite, Torbernite. Smithsonite..=45 — tGa.r3n154, G.=3'5 —3'S G.=4 -4'5 Hematite. A zurite, Bornite. G.-=4'6 G*.3'S1 Chrysoberyl. Chlorastrolite. Chrysoberyl G.=4 —-4 7 Minium. Chras e G.35-49 Zircon. G.=4'L6-4'*S G.=32't Spinel. Marcasite. Fibrolite. G.=4 -4'S Marcasite. =G8.o=3-55 Barite. G. =4'7 Dioptase. Diamond. G.=4,1 Hausmannite. G.=3t2-3e5 G. -=3'6 Brookite. G.=47 -4'8S G.=32- 3'5 Arsenolite. G.=4'1-4' 2 Braunite. Pyroxene.:Barytocalcite,. Ruffle. G.=4'S —4'9 Gpatite.35 G.=3 —3 G.=4'1 —4' 3 Pyrolusite. GApatite. =3- Strontianite. Chalcopyrite. G=4 *li 5 Chrysolite, G.=36- 3S G.=4'1 —44 Linnaeite, Vesuvianite. Libethenite. Olivenite. Pyrite. G.=3'3- 3'5 G.G=3'63-4 G.=4'2-4 3 G.=4'9 —5'1 Diaspore. Limonite. Witherite. Magnetite. G.=3'3 —37 G.=3"7 —39 G. =42 —4'4 G.=5'2 —5'3 Titanite. Siderite. Manganite. Senarmontite. G.-=3'3 —4 G. —' 3'-7-4 G.=4'3-4'4 G.=5'2 —5'6 Epidote. Malachite. Tennantite. Millerite. xiv;G. -5'-35'S G.=6 G.=6-4 —7 G.=S9 — Embolite. Scheelite. Smaltite. Cinnabar, G.=5'1-54 5 G.=6 —63 G.=6-5 - Copper. Proustite. Cobaltite. Pyromorphite. G. =9'7 G.=5'4-5' S G.=6-6'4 G.=6'6-6'7 Bismuth. Zincite. Arsenopyrite. Antimony. G*=1 —i014 G.=5'41 —6'4 G.=6'1 —6'3 G.=7 —*7 Amalgam. Columbite. Tellurium. Leucopyrite. G.=1'01 —111' l G.=5'5 G. =6'1 — 6*S G.=7 —S88 Silver. Cerargyrite, Aikinite. Clausthalite. G. = 1114 Iodyrite, I G.-=-6'* 2 G.=77 — 7-2 Lead. Valentinite. Anglesite, Mimetite. G.==55 —5*S Polyasite, G.=7-7*J Mercury. G.=5'5-6'5 G.-G-2-6,5 zn G;=15-19 Franklinite. Ullmannite. G.71-75 Gold. Wolframite. Wulfenite.-72 Platinum. Bournonite, Galenite. Pyrargyrite. G.=6. G. S4 Iridosmine..=5'S-6 Cassiterite. Ttdie Tetradymite. Bromyrite, G. =6'64 G.-=7-3-7*6 Undetermined. Cuprite. Calomel, Niccolite. Bieberite, G.=5'9 Cerussite, G.-=7'3-7' S Copiapite, Arsenic. U raninite. Iron. Molybdite, G.=5'9 —61 G.=6'4 —65 G.=-7 -S Remingtonite, Crocoite. Bismuthinite. Stolzite. XV SYSTEMS OF CRYSTALLIZATION. NO. SIMPLE FORMS. AXES. I Octahedron, or cube. 3 axes rectangular and equal. 2 T etragonal pyramid, or right prism withl 3 axes rectangular, 2 equal. a square base. 3 Rhombic pyramid, or right prism with a 3 axes rectangular, and unequal. rhombic base. 4 Tonoclinic pyramid, or inclined rhombic 3 axes unequal, 2 rectangular. prism. 5 Triclinic pyramid, or doubly inclined 3 axes unequal, and unequally inclined. rhomboidal prism. 6 Hexagonal pyramid, hexagonal prism, 4 axes, 3 equal and equally inclined, 1 or rhombohedron. at right angles to the other three. NAMES USED BY DIFFERENT AUTHORS. WEISS & DANA. DANA. NO. IOHS OS. PHILLIPS. NAUMANN. DELAFOSSE. 1D54. 1869. ROSE.1 1 Tessular. Regular. Cubic. Tesseral. Cubic. Monomet- Isometric. ric. 2 Pyramidal. 2 and I Pyramidal. Tetrago- Tetrago- Dimetric. Tetragonal. axial. 11n. nal. 8 Orthotype. I and 1 Prismatic. Rhombic. Ortho- Trimetric. Orthorhom. axial. rhombic. bic. 4 Hemior 2 & 1em- Oblique. Monoclino- Clino- Monocli- Monoclinic. thotype. bered. hedric. rhombic. nic. 5 Anortho- 1 & 1 mem- Anorthic. Triclino- Clino- Triclinic. Tuiclinic. type. bered. hedric. hedric. S Rhombo- 3 and 1 Rhombo- Hexagonal. Hexagonal. Hexagonal. Hexagonal. hedral. axial. hedral. SCALE OF HARDNESS. 1. —Talc. Laminated light green variety. Easily scratched by the nail. 2.-Gypsum. Crystallized variety. Not easily scratched by the nail. Does not scratch a copper coin. 3.-Calcite. Transparent variety. Scratches and is scratched by a copper coin. 4. —Fluor. Crystalline variety. Not scratched by a copper coin. Does not scratch glass. 5.-Apatite. Transparent variety. Scratches glass with difficulty. Easily scratched by the knife. 5.5.-Scapolite. Crystalline variety. 6.-Orthoclase. White cleavable variety. Scratches glass easily. Not easily scratched by the knife. 7.-Quartz. Transparent variety. Not scratched by the knife. Yields with difficulty to the file. 8.-Topaz. Transparent variety. Harder than flint. 9.-Sapphire. Cleavable varieties. Harder than flint. 10.-Diamond. Harder than flint. COMPARISON OF NOTATIONS USED TO ISOMETRIC REGULAR HOLOHEDRAL LEVY. Octahedron, al Cube or hexahedron, P Rhombic dodecahedron, bl Tetrahexahedron, bm Trigonal trisoctahedron, am Tetragonal trisoctahedron, am 1 1 Hexoctahedron, bl b m bn ItEMIIIEDRAL Hemi-octahedron, or tetrahedron, 1 a ilemi-tetrahexahedron, or pentagonal bm dodecahedron, Hemi-trigonal trisoctahedron,, a IHemi-tetragonal trisoctahedron, am 1 1 Iemi-hexoctahedron inclined, b' bS b, 1 1 Hemi-hexoctahedron parallel, or diploid, b bS b 1 1 Iemi-hexoctahledron parallel, or gyroid, b' bI bI TETARTOHEDRAL Tetarto-hexoctahedron. or tetartoid. I I bl bi, b xvi REPRESENT THE FACES OF CRYSTALS. SYSTEM. OCTAHIEDRON. FORMS. MIILLETR. WEISS. NAUMANN. DANA. 111 a:a: a 0 1 100 a: coa: coa coOco O 110 a: a: coa o 0O i or I hko a: na: ooa coOn in hhk a: a: ma mO m hkk a: ma: ma mO mOm hkl a: ma: na mOn mn FORMS. ~- (111) rl (a: a: a) 1 ~ c 0i k o) ~rl (a: na oa): ~ (h ko) ~rl (a: a: moa) M_ co _i in 2 2 k(h k ) rl (a: ma: ma) 2 2:: (h k 1). rl (a: ma: na) mOn mn 2 2 r~z C(hkl) ~ rl (a: ma: na) ~[m2] mn] +f (h k 1) Arl (a: a:na) mOn T n FORMS. mOn nn - vx (h k 1) ~rorl- 4 r orl.xv11 TETRAGONAL TETRAGONAL IHOLOHEDRAL LEVY. Tetragonal pyramid of the first order,t am Tetragonal pyramid of the second order, bm 1 1 Ditetragonal pyramid, bI bI hl Tetragonal prism of the first order,t h' Tetragonal prism of the second order, m Ditetragonal prism, hm Basal pinacoid, P HEMIHEDRAL Sphenoid of the first order, am Sphenoid of the second order, bn 1 1 Tetragonal scalenohedron, bm bn h1 I 1 Tetragonal trapezohedron, b m bn hi 1 1 Tetragonal pyramid of the third order, bim b h' Tetragonal prism of the third order, hm TETARTOHEDRAL Sphenoid of the third order, * r stands for right and I fbr left, to distinguish it t These prisms and pyramids or octahedra of the first order xviii SYSTEM. PYRAMID. FORMS, MIILLER. WEISS. NAUMANN.'DANA. hhl a: a: mc mP m h o 1 a: ooa: me mPoo mi hkl a: na: me mPn mn 110 a: a: coo ooP i or 1 100 a: coa: mc mPoo ii hko a: na: ooc ooPn in 001 coa: ooa: c OP O FORMS. x(h h 1) r.. (a: a: m) mPc) 2 2 M (h o 1) |r.l. (a: coa: ic) mPc mi 2 2T;x 0 hk) rh k (h l) ma: na: c) mPn mn 2 2 "~ (~h k 1) r.l.~ (ma: na: c) *r or 1" P r or l Fri~m~na:C) 1r 1 mPn r 1 mn "r (h k 1) (ma: na: c) or Tor r IoPn r r in or —- or — (h k o) r.l. (a:na: oc) 1 r 2 1 r 2 FORMS. r:iXt:(hk. 1)| | lor- ormn r -mPn- 1 r 4 from + right, and - left, in the previous forms. are those of the second in the diagrams. xix ORTHORHIIOMBIC RHOMBIC IIOLOHEDRAL LEVY. Rhombic pyramid, 1 1 Macropyramid, b~ bmN g Brachypyramid, b bI gI Rhombic prism, m Macroprism, h1 Brachyprism, gm MIacroldome, as Brachydome, e Macropinacoid, h' Brachypinacoid, g Basal pinacoid, P tIEMIHEDRAL Rhombic sphenoid. The other hemihedral forms are single xx SYSTEM. PYRAMID. FORMS. UILLEb. WEISS. NAUMANN. DAIA. hhl a: b: m mP m, * h k na: b: me mPn mn t h k l a: nb: me mPn mWin 110 a:b: ooc cP i or I *h k o na: b: ooc coPn' 1h k o a: ~nb: coo ooPn in o k ooa: b: me c mPoo v 0 h o l a: cob: m c mPoo mi 010 oa: b: ooc coPoo tz 100 a: oob: wcc oPo io 001 ooa: oob: c OP 0 FORMS. v.(h k) | na b: mc | rorl cn rorl 72i a: b: mc I 2 2 planes, or nairs of parallel planes. 8 h < k f h > k xxi MONOCLINIC MONOOCLINIC HIOLOHEDRAL LEVY. Hemi-pyrami-pyr,'id, Monoclinic pyramid, I (Hemi-pyramid, bm C 1 tHemi-orthopyramid, bm da h Orthopyramid, 1 I l Hemi-orthopyramid, bh b-, hl iemi-clinopyramid, dd b' Clinopyramid, i-clopyr 1 IHemi-clinopyramid, bm dn g' Inclined rhombic prism, m Orthoprism, hi Clinoprism, gm i Heli-orthodome, O Orthodome, Hemi-orthodome, a;~ Clinodome, em Orthopinacoid, h' Clinopinacoid, g Basal pinacoid, P The hemihedral forms are single planes or pairs of parallel planes. xxii SYSTEM. PYRAMID. FORMS. NILLEIR. WEISS. NAUMANN. DANA. hkk 1 a: b: mcmP hkk a': b:mc m hkl a: nb: mce * hkl a': nb:mc mPn ~mn thkl na: b: mc t k 1 na': b: mc n n 110 a:b: oc oP i or ] *h k o a: nb: coc coPn in th k o na: b: coc coPn in hol a:b:mc h ol a': oob:mc mPo o k coa: b: m mPoo m 100 a: oob: coo coPoo i 010 ooa:b: co c oPoo i 001 ooa: cob: c OP 0 *h > k. h < k. xxiii TRICLINIC TRICLINIC HOLOHEDRAL LEVY. Tetarto-pyramid, fW Tetarto-pyramid, d~ Triclinic pyramid, Tetarto-pyramid, b~ Tetarto-pyramid, c 1 1 Tetarto-pyramid, f dn h' 1 1 Tetarto-pyramid, d- fi h1 Macropyramid, 1 Tetarto-pyramid, blll ci Tetarto-pyramidb cI h 1 1 rTetarto-pyramid, fm cn g Tetarto-pyramid, dI buii g1 Brachypyramid, 1.1 Tetarto-pyramid, b 1i dn g' [Tetarto-pyramid, cm fJ g Doubly inclined j Hemi-prism, t rhombic prism, H lemi-prism, m 9Hemi-prism, m Macroprism, H i-p Hemi-prism. I Mh Hemi-prism, Brachyprism, Hemi-prism, Hiemi-dome, IMacrodome, Herni-dome, Om am Hemi-dome, 1 Brachydome, Helmi-dome, em Mfacropinacoid, h1 Brachypinacoid, gl Basal pinacoid, P *h>k I . Fig. 19. oo P oo. oo P. P. Leucopyrite.. lAe As2. ORTHORHOMBIC. SYN.-Arseneisen, Arsenikkalkies. The forms of the crystals are the same as those of Arsenopyrite, only differing in the value of their angles. The angle of the prism in Leucopyrite is 122~, but in Arsenopyrite it is 111~. Fracture, uneven. Lustre, metallic. Color, silver or steel-gray. Streak, grayish-black. H.=5-5.5. G.=6.8-8.71. Composition, As 72.8, Fe 27.2. Pyr. &c. B. P. In a closed tube gives As, and in an open tube Xs. On Ch., gives the odor of arsenic and in 0. F. a coating of Xs; in R. F. a magnetic globule. Gives the reactions for iron. It very much resembles Arsenopyrite, and can generally only be distinguished from it by a chemical test, in which case only arsenic and no sulphur is found. Its density is high, about 7, while that of Arsenopyrite is 6,1. FORMUL2E OF THE CRYSTALS. Pi. XXIII. Fig. 20. oP. Poo. Arsenopyrite. Fe (As, S)2. ORTHORHOMBIC. SYN. —Mispickel, Arsenical pyrites, Arsenkies, Fer arsenical. It crystallizes in the right rhombic prism of 111~ 53', with traces of cleavage parallel to the prism. The crystals are mostly prisms attached to a gangue. They may have a rounded termination, which is a union of domes, or pseudo-octahedron. The crystals are often macled, parallel, either to the prism or macrodome. They have frequently such a number of faces that they appear to be curved and striated. The brachydome is usually striated, which is very characteristic. Lustre, metallic and quite light in a fresh fracture, but it becomes dull on exposure to the air. Color silver or tin-white. Streak, grayish-black. ]H.=5.5-6. G.=6-6.4. Composition, As 46, S 19.6, Fe 34.4. Pyr. &e. B. P. On Ch., it gives arsenical fumes. The heat from stroke of the steel is sufficient to produce this odor. Heated in a tube, it gives off S and As, which condense first as a red sublimate of sulphide of As and then as a mirror of As. Heated for a long time in R. F., it gives a magnetic scoria. Decomposed by i, giving a deposit of Xs and S. Large masses of Arsenopyrite are semi-crystalline or indistinctly fibrous, they are rarely amorphous, compact and granular. It is distinguished from Marcasite by its color, its reaction for arsenic and its density, which is 6.12, while that of Marcasite is about 5. Resembles Cobaltite, but it 126 LECTURES ON MINERALOGY. can be distinguished by the crystalline form and a chemical test. It is found abundantly in the U. S. FORMULXE OF THE CRYSTALS. Pl. XXIII. Fig. 21. oo P. i P oo. The characteristic striation of the brachydome is shown on one:of the faces. Fig. 22. oo P. I Poo. Poo. Fig. 23. P o. P oo. ~iP oo. Resembles a square octahedron. Fig. 24. oo P. 1P oo. P oc. Fig. 25. Twin crystal; composition-face oo P. Horizontal projection. Fig. 26. Twin with the combination Fig. 21; composition-face P o0. Scorodite. e.Xs+4 ft. ORTIORHOMBIC. SYN.-Arseniksinter, Eisensintern It crystallizes as a rhombic prism of 98~ 2', generally in little crystals of a bluish-green color usually slightly altered. Cleavage imperfect, parallel to the brachypinacoid. Lustre, vitreous. Fracture, uneven,. Translucent. Color, pale green or brown. Streak, white. ItI=3.5-4. G.=3.1-3.3. Composition, Is 49.8, Fe 34.7, ft 15.5. Pyr. &c. B. P. In a closed tube yields 1t and-turns yellow. On Ch., fuses easily, colors the flame blue (As), and gives off arsenical fumes. Soluble in HCI. Scorodite is found in Edenville, N, Y., and in Carabas Co., N. C. FORMULXE OF THE CRYSTALS. P L xxiv. ig. 1. P. o0P co. o0 P co. _ Fig. 2. P. o P co. c P 2. Fig. 3. P. OP. o o. oo. cP2. 2P Fig. 4. The combination Fig. 1, with o P 2 and 2 P o. Pharmacosiderite. 3 Fe Xs+te ft3 +12 f1. ISOMETRIC. SYN.-Cube Ore, Wiirfelerz, Fer arseniate'. Its usual form is the cube, but tetrahedral faces have been found. The crystals are found in cavities. Its cleavages are very difficult, parallel to the cube. Its fracture is conchoidal and its lustre vitreous. Transparent. Its color is usually emlerald-green. This green becomes brown in the flame of a candle. It is sometimes found brown or honey-yellow. Streak, green, brown and yellow. It is pyroelectric. Pyr. &c. B. P. In O. F. melts rapidly to a metallic globule which is not rragnetic. In the R. F., it becomes a magnetic scoria and arsenic is given off. Soluble in acids. With the blowpipe and with acids, it is easily distinguished from the copper salts which it resembles. FORMULAE OF THE CRYSTALS, Pl. XIX..Fig. 15. Xc Oc.. LECTURES ON MINERALOGY. 127 Arseniosiderite. Oat Xss+4 Fe" As+15 ft.It is quite rare, and is found in fibrous concretions of a yellowish-brown or golden color. Lustre, silky. Streak, yellowish-brown. H.=1-2. G.=3.52-3.88. Composition, &s 37.9, Fe 42.1, Ca 11.1, At 8.9. Pyr. &c. B. P. The same as Scorodite. Siderite. Pe 0. HEXAGONAL. SYN.-Chalybite, Spathic Iron, Spherosiderite, Spatheisenstein, Eisenspath, Fer spathique, Fer carbonate, Siderose. It crystallizes in rhombohedra of 107~, with a very easy cleavage parallel to the faces of the rhombohedron. It is generally found as the primitive rhombohedron with curved faces, the curve affecting even the cleavage. It is also found in lenticular and cockscomb crystals. Its fracture is lamellar, rarely conchoidal. Lustre, vitreous or pearly. When just taken from the mine and quite pure, it is sometimes entirely white, but it soon becomes altered in the air, and takes a grayish color, which sometimes becomes brown, brownish-red or green. Streak, white. H.=3.5-4.5. G.= 3.7-3.9. Composition,'e 62.1, C 37.9. Pyr. &e. B. P. On Ch., blackens and fuises at 4.5. Heated in a closed tube, it decrepitates, blackens and gives a magnetic globule. In O. F,, the Pe becomes Pe, in R. F. becomes magnetic. With acids, it effervesces slowly when cold. It is found crystalline and compact. It was supposed for a long time, that an Araconite of iron called Junckerite existed, which was isomorphous with the carbonates of baryta, strontia, lime and lead, but it has been proved not to be well founded. It is almost to be regretted that it is not so. It is sometimes entirely black, owing to the presence of manganese. This decomposition is remarkable, since carbonate of iron and manganese when perfectly pure do not easily become peroxidized. It is also found in beds of different colors, which have been formed by the decomposition of sulphates of iron in contact with organic matter, producing Pyrite and Siderite. It generally has a lustre analogous to that of Dolomite, but its density is nearly 4, while that of Dolomite is 2.8 to 3. When found in lamellar, saccharoidal masses or granular, it resembles Calcite, but the density distinguishes it. Exceptionally, it is found fibrous. This variety is distinguished under the name of Spherosiderite; it is generally found in cavities in Basalt, forming little mamelons with a velvety surface, and a fibrous or scaly fracture. It might be mistaken for Sphalerite, but the action of acids will distinguish it. The lithoidal variety of Siderite is whitish or brownish in a fresh fracture, but is quickly altered on exposure to the air and becomes brown. Its fracture is compact and conchoidal, and is devoid of lustre. These masses have no very distinctive characteristics, and can only be distinguished by the action of acids. It is most extensively found in the coal formation, in which case it is black or brownish. When it is associated with bituminous matter, it is called Black band. One of the ordinary appearances of this variety is in the shape of Septaria. These are spheroidal, flattened and brownish masses, which have been cracked during their formation, and subsequently these cracks filled with Calcite and Quartz. It also forms pseudomorphs. It is distinguished from Dolomite and Calcite, which it resembles, by its higher specific gravity, and by giving a magnetic globule. 128 LECTURES ON MINERALOGY. Siderite is one of the most important ores of iron. It is-found in veins at New Milford, Conn., Plymouth, N. H., and Stirling, Mass., and other places. The argillaceous variety is very abundant in the coal formation. FORMULAE OF THE CRYSTALS. Pl. XXIV. Fig. 5. R. Faces usually curved. Fig. 6. R. OR. Mlenaccanite. (Ti, Fe, Mn, Mg)2 03. HEXAGONAL. SYN.-Washingtonite, Crichtonite, Ilmenite, Titanic Iron, Titaneisenstein, Titaneisen, Eisenrose, Iserin, Basanomelan. It crystallizes as a rhombohedron of 856 40';. It has a number of derived forms, many of which are hemihedral and twins. Lustre, metallic. Color, bluish-black. Streak, black or reddish-black. 1lI.=5.6. G.= 4.5-5. The composition varies greatly. Pi 10-59, Fe 1.2-82.47, Pe 1.5-50.17. Pyr. &c. B. P. It is infusible; with S.Ph. in the 0. F. it is dissolved. In R. F., it gives a bead, which is colorless when hot, but dark violet on cooling. When pulverized and heated with IC1, it is slowly dissolved to a yellow solution, which, when filtered and boiled with tin, becomes blue. It has the same general characteristics as Mlagnetite, except perhaps that it is a little bluer and does not attract the magnet. The crystals, which are quite rare, are sometimes very large, and generally have a. reddish tinge on the surface, owing to a partial decomposition. It is frequently found as a sand. It is very rare that Magnetites do not contain some trace of Titanic Iron. It is also frequently found in the other ores of iron, as in Hematite, for in almost all of the furnaces where these ores are used, nitroeyanide of titanium is found. It has less lustre than Hematite, and has a black streak. It is of little value as an ore of iron, as it is too refractory to smelt in large quantities. It is found in large crystals.in Orange Co., N. Y., also at Washington and elsewhere in Conn., and in Mass. and R. I. FORMULAE OF THE CRYSTALS. P1. XXIV..Fig. R. OR.. -2R. OR. Fig. 9. 5R. R. OR. Chromite. (Pe, Or, I~g) (3A1,.e, ir). ISOMETRIC. SYN.-Chromic Iron, Chromeisenstein, Fer chromate. It is one of the Spinels of iron, a sort of Magnetite, in which the Pe is replaced by Br, and 3l1. It has the same forms as Magnetite,.but is not so frequently crystallized nor so perfectly. Its usual form is the octahedron, more rarely the cube. Fracture, uneven. Lustre, semi-metallic. Opaque. Color, brownish-black. Streak, brown. Sometimes slightly magnetic. H,=5.'5. G,-=4.321-4.498. Composition, for the formula Pe:'r, -le 32, Jr 68. Pyr. &e. B. P. In O. F. infusible; in R. F., slightly rounded: on the edges and becomes magnetic. With fluxes, gives the reactions for chromium, which distinguish it from Magnetite. It is not attacked by acids. LECTURES ON MINERALOGY. 129 It resembles Magnetite and cannot be distinguished from it with certainty, except by its chemical properties. It is perhaps a little blacker than ordinary Magnetite, but this is only an external character, which may not hold good. It is often found as a sandl composed of octahedral crystals. It is used for the manufacture of pigmnents. It is fbund in Vermont, Massachusetts, Connecticut, Pennsylvania, Maryland and elsewhere. Columbite. (e, Sin) (0b, Ta). ORTHORHOMBIC. SYN. —Niobite. Crystallizes as a right rhombic prism of 101~ 26'. The forms which'predominate are those of the square prism, the angles of which are frequently so highly modified, as to appear rounded. It has cleavages parallel to both macro and brachypinacoids. Fracture, uneven. Lustre, submetallic. Opaque. Streak, dark red to black. Il.=6. G.=5.4-6.5. Composition, for le O'b, 1e 21.17, Tb 78.83. The columbic acid is always in excess. Pyr. &c. B. P. With borax it is dissolved, giving the reactions for iron. If flamed in the R. F., gives a grayish-white bead, or, if there is an excess, the bead becomes opaque without flaming. Its very dark color and a slight iridescence which is almost always found on the specimens, distinguishes it from other minerals. Its principal localities in the'U. S. are Haddam and Middletown, Conn., where it occurs in crystals and in pieces of considerable size in the Feldspar. quarries. FORMULXE OF THE CRYSTALS. PI. XXIV. Fig. 10. oooo. oor3. oPoo. OP. 3P3. P. IPo. -ig.11. ooc-n. oocP. coP. p ooP-3. OP. P. 2Pco. P o. Fig. 12. oX Poo P'. i cW. P. oo P oo. 2 P. o'3. P. Fig. 13. ooPoo Poo. Pco. 2 Poo. o P. P. 3 P -. o. 2P 3 P3. Fig. 14 ooPoo. ooPco. coP2, coP. P3. Wolframlite. 2 Fe W+3 In W or 4 Se W+'Sn W. ORTHORaHOMBI SYN.-Wolfram. Its primitive form is a right rhombic prism of 101~ 5', with a very easy cleavage parallel to the brachypinacoid, which gives it a lamellar'structure, and another perpendicular to it, which is not so easy. The crystals usually show the prism and macrodome very prominently, but are rarely complete. They are usually striated, on account of the easy cleavage parallel to the brachypinacoid. They show the hemihedry with parallel faces. They are often macled -and, as this macle is not parallel, the cleavage shows reentrant angles. Lustre, se'mi-metallic. Opaque. Color, dark grayish or brownish-black. Streak, dark reddish-brown or black. It is sometimes slightly magnetic. H.=5-.55. G.=7.1-7.55. Composition, for the first formula, W, 75.33,'e 9.55, Sin 15.12; for the second, IV 76.2,'e 5.6, Mn 17.94. Pyr. &e. B. P. Fuses at 2.5-3 to a globule studded with crystals. With borax and S.Ph. gives the reaction of tungstic acid, red when 9 130 LECTURES ON MINERALOGY. hot, yellow when cold. It is attacked with difficulty by acids, and gives up tungstic acid when cold. It is also found in lamellar masses made up of imperfect crystals. Its density fracture and streak distinguish it from Hematite and Magnetite, which it very often resembles. It has been found in Munroe, Trumbull, Conn., also in Maryland, N. Carolina, and Missouri. FORMULAE OF THE CRYSTALS. Pl. XXIV. Fig. 15. coP. coPoo. jPoo. Poo. Fig. 16. oo P. jPo. o P mo. co P 2. P oo. P. 2 P 2. Fig. 17. Twin crystal; composition-face c Poo. ig.. 18. Twin crystal; composition-face t P co. MANGANESE. lBraunite. SIn Mn, or in. TETRAGONAL. SYN.-Hartbraunstein. It crystallizes as an octahedron, the angle of which is 119~ 46'. It is not isomorphous with Hematite, which is hexagonal. Some of the varieties show an obscure octahedral cleavaoe, but crystals are comparatively rare. They are generally octahedra, which are less acute than those of Hausmannite; they frequently show the base, and have curved faces. Smaller crystals are sometimes found with the octahedron and di-octahedron. It has an uneven fracture and a metallic lustre, which is sometimes quite distinct. Opaque. It is black, with more or less of a bluish or brownish tint. Its streak is brown into black, without any tinge of red, which distinguishes it from Hausmannite, which is often found on the same specimen. H.=6-6.5. G.=4.75-4.82. Composition, Mn 86.95, O 9.85, Ba 2.25. ft 0.95. Pyr. &c. B. P. Infusible and does not give off ft. With fluxes, gives the reactions for Mn. The non-oxidizing acids hardly attack it and give off only a little C1. With HC1, C1 is evolved. When it contains Rhodonite, gelatinous silica is deposited. It is almost always found in granular masses, of a bluish-black color. The grains are very small and do not show cleavage. The bluish lustre will distinguish them from Magnetite and Hematite, but the color of their streak is a better distinction. Like Alabandite, Braunite is often found in little veins in the silicate or carbonate of manganese, as a product of their decomposition, in which case it is very impure and gives up ~gelatinous silica, or even effervesces slightly. It is also found associated - with other minerals of manganese, as the violet variety of Epidote, tihe Titanite containing manganese, and Hausmannite. Hausmannite. SIn" Mn. TETRAGONAL. SYx.-Glanzbraunstein. The angle of-the octahedron is 1050 25'. It is the red oxide of man-,gauese of the laboratories. It has an easy cleavage parallel to the base,and octahedral cleavages, which are more difficult. The simple crystals,are octahedra, which are sometimes truncated. They are often grouped'2 by 2 or 4 by 4, the twin plane being parallel to the octahedron. Its fracture is uneven. Lustre, submetallic. Opaque. Its color is generally brown, almost black. Streak, chestnut-brown, almost red. H1.=5-5.5. "G.=4.722. Composition, Mn 72.1, O 27.9. Pyr. &c. B. P. Alone, it is infusible. With the fluxes, gives the LECTURES ON MINERALOGY. 131 reactions for Mn. The non-oxidizing acids attack it, giving but little C1. HC1, gives C1. Besides the crystals, crystalline masses are found which sometimes show the points of crystals; often in others there are no crystals but only cleavages. They are often deep black, which easily distinguishes them from the oxides of iron. If it is crystallized, the acute octahedra are easily distinguished. The best and most distinctive characteristic is that of its streak, which is dark reddish-brown with the red color most distinct. Sometimes these masses resemble Magnetite, but are distinguished because they are not magnetic, and Magnetite has a black streak; the red of Hematite is quite different. XWolframite, which sometimes resembles it, has a much higher density and a dark violet streak. FORMULAE OF THE CRYSTALS. P1. XXIV. Fig. 19. P. Fig. 20. Twin crystal; composition-face P o. P1. XXV. Fig. 1. Twinning repeated with four individuals. Pykolusite. - n. ORTHORHOMBIC. SYN.-Weichmanganerz. It crystallizes as a right rhombic prism of 93~ 40', with a cleavage parallel to the brachypinacoid. The crystals are always implanted in a gangue and only show their ends. It is sometimes found in radiated bacillary masses, showing in their fracture a lustre which is at the same time metallic and silky, with a gray iron color. Its fracture is irregular and unequal. Lustre, metallic. Opaque. Color, iron-black or dark steelgray. Streak, black. H.=2-2.5. G.=4.82. Composition, Mn 63.3, 0 36.7. Pyr. &e. B. P. Is infusible, gives off no water. With fluxes, it gives the reactions for Mn. It is very fragile, stains the fingers black and is easily broken up with the nail. It is also found concretionary, sometimes in tubercular masses. Sometimes in stalactites, when it is usually cavernous. It is made up of concentric beds of fibres fastened together at the surface, which is smooth, and the adhesion is consequently not very great. Such masses are very tender, their fracture is fibrous; sometimes. it is compact when impure. It is also found amorphous, in large masses disseminated in earthy matter. It is then intensely black without lustre, showing sometimes in the fresh fractures a sliguht semi-metallic reflection, resembling several metallib sulphides. It is only distinguished by its streak and blowpipe reactions. It is found in all the -geological formations, probably produced by the decomposition of the carbonate, as little masses and frequently as dendrites. It resembles Psilomelane, but is distinguished by its inferior hardness. From the ores of iron, it is distinguished by the blowpipe. It is used in glass works for making bleaching powders and also for the manufacture of oxygen. It is found in many of the iron mines of the U. S., forming a velvety coating usually on Limonite. FORMULE OF THE CRYSTALS. P1. XXV. Fg. 2. cP. opeoo. QoYPC. Po. OP. 132 LECTURES ON MINERALOGY. 1)langanite. Mn A-. ORTHORHOMBIC. SYN.-Acerdese. It crystallizes as a right rhombic prism of 99~ 40', with an easy cleavage parallel to the brachypinacoid, and another more difficult, parallel to the prism. It is usually well crystallized. The crystals are usually formed by the faces of the prism, frequently terminated by a macrodome or an octahedron. Generally, however, the crystals have a very much larger number of faces, which produce very marked striations on the vertical faces, so that they are often fluted and rounded. The crystals which have the basal terminations are frequently joined together parallel to the prism. The common base is in that case striated and undulated, by the projection of the terminations of the different crystals. The crystals in such a case are very much striated and frequently very large. It also shows macles, formed by a hemitrope parallel to the brachydome. It is also found in bacillary masses, made up of crystals diverging from a common center. Its fracture is uneven. Lustre, semi-metallic. Opaque. Color, darkbrown or iron-black. Streak, reddish-brown to nearly black, darker than Limonite. Its color' is intermediate between that of Braunite and Hausmlannite, and might result from a mixture of two. It is well in the presence of such a powder to seek for water. Pyr. &c. B. P. In a tube gives off Ai, and is then infusible; this distinguishes it from the other oxides. With fluxes, it gives the reactions for Mn. In acids, even before calcination, it is dissolved and gives off C1. It is also found concretionary and stalactitic, resembling the forms of Pyrolusite, but usually harder. The distinction is easily made by the color of, the streak and the presence of water. It is found also as very small crystals imbedded in compact Manganite, which has a granular fracture, which may also be unequal. The mineral is then in concentric layers. It is also found in amorphous masses, which may be distinguished from Pyrolusite by their hardness, their streak, and the presence of water. Psilomelane often contains a considerable amount of Manganite, which is the reason why it gives off so much water. Manganite is found very abundantly in nature, but it:givestoo little chlorine to be used as a -substitute for Pyrolusite.; it does not pay the.expenses of working. -FORMULtE OF THE CRYSTALS. Pt. XXV.' Pig. 3. ooP. ooP2. ooP'2. P3. 2P.. 2P2. -P 2; the last form is hemihedral, as a rhombic sphenoid. Fig. 4. Horizontal projection of the preceding combination. Fig. 5. Twin crystal; compositionface parallel to the vertical axis. Fig 6. Twin crystal; composition-face P Ci. Psilomelane. (Ba Nin) in + Mn + nil SIn. SYN. -Iartmanganerz. It is never crystalline, but massive and botry.oidal; sometimes the free Pyrolusite which is mixed with it, shows traces of crystallization. This formula is the one around which the mineral varies. It appears to be a mixture in variable quantities of Pyrolusite, and Pyrolusite combined with bases, which are most generally Ba, sometimes Ca, rarely alkalies or A1, LECTURES ON MINERALOGY. 133 with a variable.proportion of water. Not having a very well defined composition, it has no very fixed characters. It is harder than Pyrolusite, and sometimes even strikes fire with the steel. This is owing to the presence of silica, which separates in a gelatinous state when it is treated with acids. Lustre, submetallic. Opaque. Color, iron-black. Streak, brownish-black and shining. H.=5.6. G-=3.7-4.7. Composition, Mn and MnI 81.8, O 9.5, J 4.5, ff 4.2. Pyr. &c. B. P. In a closed tube yields Af. Loses oxygen by ignition. Gives the reactions for Mn. Yields Cl with HC1. It appears to be a product deposited by mineral waters. There is now at Luxeuil, in France, Thermal Springs which abandon a. deposit, which is quite analogous, produced by the decomposition of MIn held in' solution. This spring holds in solution also the earthy carbonates and silica. The deposit which forms is compact and is quite comparable to Psilomelane. It is also found in concretions reserrbling Pyrolusite, on breaking which, fibres are found, which are generally pure Pyrolusite. It is also found in compact masses, with a variable fracture, and with characters quite analogous to those of Pyrolusite, generally black with a black streak. Its hardness distinguishes it. In these compounds the Mn seems to act like an acid and to saturate bases. It has the same uses as Pyrolusite. Wad. Pt Rn+fl. It=l, Ba, 0o, Mn. SYN.-Bog Manganese, Asbolite, Asbolan, Kobaltmanganerz, Schwarzer Erdkobalt, Lampadite. This mineral is found in nature in two different states. It is sometimes in large amorphous masses, brown nearly black, which soil the fingers with a chocolate-brown powder. It has such a low density, that it is frequently called Cork Manganese. It is easily cut with a knife, but can hardly be pulverized with a pestle, for it shows a certain degree of elasticity. It has no lustre. It frequently contains to, and is then called Earthy Cobalt. Sometimes it contains Cu. It is often very light and soils the fingers. Its color is a dull bluish or brownish-black, or reddish-brown. H.=0.5-6. G.=3-4.26. Composition, Man Mn 79.12, O 8.82, ]a 1.4, f110.66. Pyr. &c. B. P. Acts like Psilomelane, the varieties containing do or Cu react for these metals. Treated with HCI, gives off C1. It may sometimes be found as a concretion. It seems to have been a muddy deposit, which has afterwards become dry, for the masses are usually very much cracked. When it is found in large masses it can be profitably used in commerce, for it is easily soluble and gives off a great deal of C1. In some of the Limonite mines, it is found in a condition totally different and has a silvery look. It is then called Silvery Manganese. It is found on the surfaces of the ore, as a velvety covering, with almost a metallic lustre. WVith the glass, little soft elastic scales of very thin Wad are distinctly seen. In some localities the one passes into the other, and the entire mass is then compact, with traces of a silvery lustre. It is used for making Cl, but is too impure to make oxygen. It is sometimes used as a paint. It is found abundantly in N. Y. and N. H. DISTINCTION BETWEEN THE OXIDES OF MAN'GANESE. —These oxides of Manganese are very difficult to distinguish with the blowpipe, as they all give the same violet bead with fluxes. Manganite is distinguished by giving off water, from Braunite, Hausmannite and Pyrolusite. Wad is distin 134 LECTURES ON MINERALOGY. guished especially by its lightness; for all the others, the. best distinctions are taken from the color of their streaks. HAUSMANNITE.-Acute octahedra with plane faces; traces of cleavage; streak brownish-red. BRAUNITE.-Octahedra, curved faces without cleavage; granular with a bluish-black color; streak, brown. PYRoLusITE. —Tender; stains paper black. MANGANITE.-Black, with no bluish color; fracture granular; streak, brown. Iardness greater than the others; gives off water. WAD.-Light; soils the fingers chocolate-brown and gives off water. The only remaining oxide is PSILOMELANE which has no very distinct characters. It is generally necessary to make a chemical test for Ba, by treating with HCl and then with'S. Its hardness is generally greater than that of the other oxides. Alabandite. MnS. ISOMETRIC. SvN.-Alabandine, Manganblende, Manganese sulfure. It is sometimes found in nature in cubes and octahedra and in crystalline masses which are lamellar and have an easy cubical cleavage, but crystals are quite rare. Its fracture is uneven. In its fresh fracturles, it has a metallic lustre with an iron-gray color. It becomes tarnished black or brown in the air. The streak is a characteristic green. Hi.=3.5-4. G. =3.95-4.04. Composition, Mn 63.3, S 36.7. Pyr. &c. B. P. In an open tube, gives S; is fusible with difficulty on the edges. In 0. F., it is hardly roasted, but after the roasting, during which some g is given off, the red oxide of Mn gives Mn reactions. With soda and nitre it gives a green color; with borax, a violet glass. Soluble in dilute A, giving off HS. It is a very rare mineral and is found in a semi-crystalline state, associated with other minerals of Mn, the silicate and carbonate. The Alabandite is deposited in gray veins or patches through the latter, which gives it a peculiar look. This is one of the empirical means of distinguishing it. Triplite. Rs i+ R4 F. ORTHORHOMBIC. SYN.-Eisenapatit, Eisenpecherz, Zwieselit, Manganese phosphate. -This is the usual phosphate of manganese. Cleavage unequal in three directions, perpendicular to each other. Fracture, small conchoidal. In,the fresh fractures, it is of a violet color, which is often intense, but-as soon as it is exposed to the air, it becomes black or dark-brown. It is always opaque. The fracture and the lustre are resinous, especially in the varieties which have been altered and which do not show mrruch cleavage. Opaque. Streak, yellowish-gray or brown. Very fragile. 1H.=4-5.5. G.=3.44-3.8. Composition, P 32.8, Pe 31.9, Mn 32.6, Ca 3.2. The P of this formula is'e and Mn; the R is Ca, Mg, Fe. Pyr. &c. B. P. Fuses easily at 1.5 to a black magnetic globule. Gives the reactions for chromium, iron and phosphoric acid. With g gives HFI. Soluble in HC1. The phosphates of manganese are the products of a more or less advanced decomposition. They are always impure and contain a more or less amount of iron. Its resinous lustre is characteristic, which, joined to the brownih-black color, allows it to be immediately distinguished. LECTURES ON, MINER A-LOGY. 135 Only one substance, Uraninite, has this color with the resinous lustre, but it is easily distinguished by its density, which is above 6.5, while that of Triplite is about 4. Rhodochrosite.. An,. HEXAGONAL. SYN.-Dialogite, Himbeerspath, Rosenspath, Manganspath, Manganese carbonate. It crystallizes in rhombohedra of 106~ 51', frequently with curved faces. It has a rhombohedral cleavage, which is sometimes curved, but it is not easy. The crystals are usually very small, and the usual one shown is the rhombohedron./ They are generally grouped and inter, penetrated one with the other, making spherical mamelons, and forming a coating on a gangue, which is. usually Barite or Quartz. On these coatings the points of crystals are sometimes seen, which have a velvety lustre. The fracture of these little mamelons is semi-lamnellar or fibrous. The fracture is: ordinarily uneven, sometimes fibrous and rarely compact. It is quite brittle. Lustre, vitreous or pearly on the fracture. Translucent. Opaque. Its colors are rose, which may be more or less dark, yellowish-gray, dark red or brown. Streak, white. HI.=3.5-4.5. G.3.4-3.7. Composition, a 38.6, SM/in 61.4. It is rarely ever pure, and usually contains Ca and MIg. Pyr. &e. B. P. Decrepitates a little, becomes black and is infusible if it is pure.: When it. contains silica, it sometimes fuses slightly. It effervesces easily with acids, but not as easily as Calcite, as it: must be heated a little. Sometimes it occurs as an imperfect coating, which is pulverulent and earthy, slightly colored, and generally mixed. with Calcite. The lamellar masses resemble Calcite, but the. color and density distinguish it. It is often mixed with Siderite, Magnesite or Dolomite. It decomposes on exposure like the silicate, and is then covered with black spots of the different oxides, or of the sulphide, which is easy to determine by the color of the streak. It is found in Vermont, Massachusetts, New York and elsewhere. COBALT. Linnaeite. 2 Co S+Co S. ISOMETRIC. SYN.-Cobalt Pyrites, Siegenite, Kobaltkies, Kobaltnickelkies, Cobalt sulfure. It has an imperfect cubical cleavage. The ordinary form of the crystals is the octahedron, which, with the cube, always has plane faces. Its forms are usually holohedral. The fracture is unequal. Lustre, metallic. The color is gray, with a slight rosy tint, but becomes red by tarnish. Streak, blackish-gray. ]IH.=5.5 G.=4.8-5. Composition, S 4.2, Co 58. Pyr. &c. B. P. In O. F., it is.roasted, but does not show any traces of As or Sb. In the R. F., it gives a magnetic residue, and with fluxes the reactions for Co. It is insoluble in the non-oxidizing acids, but in 1 it is dissolved, giving a rose-colored liquid and deposit of sulphur. It is sometimes accompanied by other minerals of cobalt, or associated with a gangue. It has been found at: Mine la Motte, in Missouri, and-at Mineral Hill, Maryland. FORMULAE OF THEE CRYSTALS. Pl. XXV. fig. 7. 0. Fig. 8. 0. oo 0 co; the most frequent form. 136 LECTURES ON MINERALOGY. Bieberite, (do, g) + 7 Sf. MoNocLINIC. SYN.-Cobalt Vitriol, Red Vitriol, Kobaltvitriol, Cobalt sulfate'. It is usually found as a product of the alteration of Smaltite. It is a very incoherent mass with a styptic taste, and is generally found as a pulverulent coating. It usually contains Fe S. Lustre, vitreous. Translucent. Color, flesh and rose-red. G.=1.924. Composition, g 28.4, Oo 2.5.5, f 46.1. Pyr. &e. -B. P. Yields if and at a high heat, I. Gives the reactions for Co. It is rather a product of decomposition than a mineral. Smaltite. (Co, Fe, Ni) As2. ISOMETRIC. SYN.-Smaltine, Chloanthite, Speiskobalt, Cobalt arsenical. It occurs in crystals, the dominant form of which is generally the cube, but it always has octahedral faceswhich are convex,while those of Linneite are plane. It is also found massive, with various imitative shapes. The cleavage is distinct, parallel to the octahedron and in traces, parallel to the cube. Lustre, metallic. Fracture, granular and uneven. Color, generally a silver or tin-white, sometimes iridescent or grayish from tarnish. Streak, grayish-black. H.=5.5-6. G.=6.4-7.2. Composition, As 72.1, Co 9.4, Ni 9.5, Fe 9.0. Pyr. &c. B.' P. On Ch., it gives As, and fuses to a globule. In a tube, it gives an arsenic mirror. With the fluxes, it affords the reactions for Co, Fe, and Ni. It is not attacked by the non-oxidizing acids. The slightly crystalline masses usually have a reticulated structure. It is also found in amorphous masses of a steel-gray color. It is sometimes covered with a green coating, which results from the nickel that it contains. It is also found in masses, which have a semi-granular or semi-lamellar fracture. There is a great resemblance between these masses, Linneeite and Native Bismuth; but Linnaeite is less lamellar and does not give off As; Bismuth is redder and cleaves in three directions and has a lamellar fracture. From Arsenopyrite and Leucopyrite, it can be easily distinguished by the crystalline form and blowpipe reactions. It has been found in the U. S., at Chatham, Ct. It is used for making smalt; hence its name. FORMULE OF THE CRYSTALS. Pl. XXV. Fig. 9. coO o0. 0; the most usual form. Fig. 10. 0 co0. oo0. Cobaltite. Co ( S, As ) ISOMETRIC. SYN.-Cobaltine, Kobaltglanz, Glanzkobalt, Cobalt gris. The form of the crystals is the same as that of Pyrite, and it occurs in the same combinations. It shows the hemihedry of parallel faces in its crystals, which are well defined and which are its usual mode of occurrence. It has a cleavage, parallel.to the cube, so that in masses it is always lamellar. The crystals are frequently octahedral, but they always have the faces of the hemi-tetrahexahedron. The faces of the cube are usually striated as in Pyrite, but those of the octahedron are smooth. The hemihedry distinguishes it from Linneeite, which has the same metallic lustre, but which is holohedral. It has the same formula as Arsenopyrite, but is not isomorphous with it, although it always contains some iron. LECTURES ON MINERALOGY. 137 Lustre, metallic. Fracture, uneven. Color, silver-white, often a little rosy and also grayish, if much iron is present. Streak, grayish-black. H.=5.5. G.=6-63. Composition, As 45.2, Co 35. 5, S 19.3. Pyr. &c. B. P. In a closed tube is unaltered; but in an open tube gives S and a crystalline sublimate of is. On Ch., affords fumes of S and As and fuses to a magnetic globule. %With the fluxes gives the reactions for Co, Ni and Fe. It is soluble in warm 1, giving a rose-colored liquid and depositing As and S. It is used in the manufacture of smalt and for painting porcelain. FORMULTE OF THE CRYSTALS. Pl. XXV. oo02 Fig. 11. 2 - coO co; the most usual and characteristic form. co02 Fig. 12. 0. I2 F ig. 13. The same, with the two forms equally coO2 carried'out; also a characteristic form. Fig. 14. 2. 0. ~ g. 15. ~O o. O. o02 coO4 204 00 000. 0. 2.O 2' 2 2 Erythrite. OoS ss+ 8 Bf. MONOCLINIC. SYN. —Erythrine, Cobalt Bloom, Kobaltbldthe, Cobalt arseniate'. It has an easy cleavage, parallel to the clinopinacoid and is isomorphous with Vivianite.'Lustre on the clinopinacoid, pearly, on the other faces adamantine, also dull or earthy. Transparent, translucent. It has a violet-rose color which is entirely characteristic, sometimes having the color of peach blossoms; sometimes greenish-gray. Streak, a little paler than the color. These small crystals are frequently grouped in such a way as to give the mineral a velvety appearance. The crystals are always very small. IU.=1.5-2.5. G.=2.948. Composition, Xs 38.43. Co 37.55, It 34.02. Pyr. &e B. BP. In a closed tube it loses water, and from a rose color passes to a dark violet. In R. F., it gives off As. In acids, it dissolves without effervescence and without residue. Generally it is a rosy efflorescence on other mineralsof cobalt. It often colors other minerals; it requires only 1 or 2 % to give a decided color. Remingtonite. Co C+A q This is the same carbonate which is obtained in the laboratories. It colors certain limestones, in which it enters to the extent of 4 to 5 %This same color may be produced by Erythrite. The difference is difficult to distinguish by the eye, but can be distinguished by the blowpipe. It is soluble in HC1, and gives decided reactions for iron. Cobalt is distinguished by the borax bead. Generally the specimens are nothing but Aragonite, slightly colored. It resembles Kermesite, but this volatilizes entirely before the blowpipe. It resembles some varieties of Cuprite, but is distinguished by the reactions with borax. It has been found at Finksburg, Md., at Chatham, Conn., and Mine la Motte, Missouri. 138 LECTURES ON MINERALOGY. NICKEL. Millerite. Ni S. HEXAGONAL. SYN.-Capillary Pyrites, Haarkies, Schwefelnickel, Nickel sulfur6. It is generally crystallized and perfectly pure. It has traces of a rhombohedral cleavage, which is generally almost impossible to determine, on account of the very small size of the crystals. Its lustre is metallic. Color, brass-yellow and often with an iridescent tarnish. Streak, bright. ].-.=3-3.5. G.=4.6 - 5.65. Composition, Ni 64.9, S 35.1. Pyr. &c. B. P. In an open tube it gives sulphurous fumes; on Ch., after roasting in O. F., it gives in R. F. a magnetic globule. It is attacked by the non-oxidizing acids and gives the green color of nickel. It can readily be distinguished from Pyrite by the disposition of its crystals, which are always capillary, sometimes extended on the gangue, and sometimes adhering by one extremity only and diverging. It is frequently called Capillary Pyrites. It is found with other metallic sulphides, Pyrite, Tetrahedrite and especially with Pyrrhotite, in which it appears to replace a portion of the Fe S, and is one of the principal ores of nickel. To be certain of the presence of nickel, the mineral must first be roasted, and then fused with:borax or S.Ph. If there is no nickel, the result is a yellow glass not very highly colored; when there is, the glass is violet in the oxidizing flame, and gray in the reducing flame. It is found in capillary fibers at Antwerp, Jefferson County, N. Y., and in coatings of: a radiated structure having a tufted appearance, at the Gap mine, Pa. Niccolite. Ni As. HE XAGONAL. SYN.-Copper Nickel, Kupfernickel, Rothnickelkies, Nickeline., Crystals are exceedingly rare; it is usually found amorphous. On the fresh fracture the lustre is bright and metallic, but the surfaces become tarnished by exposure. They are often covered with a greenish coating of Annabergite, which can be used as an empirical character for distinguishing it. It is always opaque. Its color is a light copper-red, which is quite characteristic. The intensity of the color, however, is variable and is subject to tarnish; those specimens which contain antimony are much darker, while those containing arsenic are paler. Streak, pale brownishblack. 1 H.=5-5.5. G.=7.33-7.671. Composition, Ni 44.1, As 55.9. Ni As must be regarded as a general formula, for Niccolite is one of the hybrid species, in which arsenic and antimony replace each other, as the mineral may contain one atom of both together, or one atom of only one combined with one atom of nickel. Pyr. &c. B. P. On Ch., it gives off a garlic odor with white vapors, if it contains arsenic; when antimony alone is present, which is very rare, there is only a coating of antimony without any odor. It is soluble in aqua regia. The copper-colored mineral is often associated with a- tin-white mineral which is Rammelsbergite, Ni As'. This is one of its most characteristic associations. The color might cause it to be mistaken for metallic bismuth, which, however, is almost always crystalline, and has a density about 9. It is found at Chatham, Conn. LECTURES ON- MINERALOGY. 139 Ullmannite, Ni (S, As, Sb)2' ISOMETRIC. BYN.-Nickel Stibine, Nickelantimonkies, Nickelspiessglanzerz, Antimoine sulfure nickelifere. It Is another of the hybrid species, in which Ni, Co, Mn, Fe, As, Sb and S may- replace each other in every proportion. It has traces of a cubical cleavage. It is sometimes found in crystals; they are generally rounded cubes, on which octahedral faces are sometimes seen, which also are rounded. On the fresh fractures it has a metallic lustre and a tin-gray color, which however becomes dull. The natural surfaces are almost always altered and are covered with a greenish or reddish coating, which is an arsenite of nickel or cobalt. Pyr. &c. B. P. Heated in a tube, it gives the orange-colored coating of As S and a black mirror of As or Sb. On Ch., it gives off white vapors of As and Sb and is then reduced to a magnetic cinder. Decomposed by f~ and gives a green solution with separation of sulphur. It is sometimes found in reticulated masses, which are frequently full of hollows. It is sometimes in masses of irregular structure, which resembles Arsenopyrite, from which it is distinguished by its density as well as by its fracture, which is irregular, while that of Arsenopyrite is lamellar. A chemical test, however, is always safest. A inuabergite. rii' s+8 fI. MONOCLINIC. SYN.-Nickel Ochre, Nickeloker, Nickel arseniat6. It is isomorphous with Erythrite. It is an accidental product and is found on other minerals of nickel, as a greenish efflorescence, with a color which is more or less intense. The pale varieties are usually mixed with free is. When they are treated with boiling water, the intense green color of the mineral becomes evident. Streak, greenish-white. Composition, Ni 37.2, Is 38.6, 1H 24.2. Pyr. &c. B. P. In a closed tube gives off water. Fuses easily. and gives a metallic globule, which gives the reactions for Ni. It is soluble in acids. It might be confounded with some of the ores of copper, but is distinguished by its chemical characters. This is soluble in acids with the characteristic colors of Ni. It has been found at Chatham, Ct. Zaratite. - i e+2a i A+~4 f. SYN.-Texasite, Emerald Nickel, Nicckelsmaragd. It is found as a crust, which is sometimes mamelonated. It has a vitreous lustre. Transparent to translucent. Color, emerald-green. Streak, paler than color. H.=3-3.25. G.=2.57-2.693. Composition,, i 59.4, C 11.7, It 28.9. Pyr. &c. B. B P. In a closed tube yields fT and C; infusible, gives the reactions for nickel. Soluble with effervescence in dilute IICI, when heated. It is quite rare, except at Texas, Pa., where it is found in Serpentine, associated with Magnesite and Dolomite. ZINC. Zincite. 2n. HEXAGONAL. SYN.-Red Zinc Ore, Rothzinkerz, Zinc oxyde. It is. the same oxide which is produced in the laboratories and in metallurgical operations. It is red, however, owing to the presence of a 9 40 LECTURES ON MINERALOGY. certain proportion of the oxide of manganese, which is always mixed with it, probably as Mn. It is always found as crystalline masses, having cleavages parallel to the hexagonal prism, and another very easy one, parallel to the base, so that the masses are always lamellar, cracked and striated. In the fracture it has a bright, almost adamantine, lustre, and is translucent o.n the edges. Its color is characteristic, it is a dark orangered, somewhat brown. Streak, orange-yellow. H.=4-4.5. G.-5.435.7. Composition, Zn 80.26, 0 19.74. Pyr. &c. B. P. Heated in a closed tube bleaches, but resumes its color on cooling. Infusible. In the R. F., gives metallic zinc, Which volatilizes, oxidizes, and forms a white ring. Gives a green color with nitrate of cobalt. Shows the reactions for manganese. Soluble in acids. It resembles somewhat red Stilbite, but is distinguished by its infusibility and its associations. It is used as an ore of zinc. It is found in masses in limestone at Franklin, N. J. It is also found associated with Franklinite at the same place.:Sphalerite. Zn S. ISOMETRIC. SYN. —Blende, Black Jack, Zinkblende, Zinc sulfure'. It is found crystallized, lamellar, compact and concretionary. The crystals are usually disseminated in a gangue, or united, to form large crystalline masses which are always more or less lamellar. The crystals show the hemi-tetragonal trisoctahedron, or the tetrahedron and cube; it is usually found as a rhombic dodecahedron. The simple forms of Sphalerite are relatively rare. They are usually composite forms resulting from complicated laws of derivation, and, what renders them even more complex, they are often macled and hemitrope. One of the most frequent of these results from the hemitropy of the combination of the rhombic dodecahedron, and the tetragonal tris-octahedron producing a figure of 24 faces, 12 of which are triangular belonging to the tetragonal trisoctahedron, and 12 tetragonal, P1. XXV. Rig. 24. It shows the hemihedry of inclined faces, giving generally tetrahedral forms. It has as easy cleavage parallel to rhombic dodecahedron, and a difficult one parallel to the octahedron. Fracture, conchoidal. Its lustre is very bright. In the clear varieties it is sometimes adamantine, and in the dark varieties it is almost metallic; sometimes it is resinous. Its colors are very variable, it is rarely colorless, but is generally honey-yellow, brown, black, red and green. When pure it is generally white or yellow. The variation in the color corresponds to a want of homogeneity in composition. The yellow variety sometimes contain cadmiuif, and all contain a very variable proportion of iron. Whatever may be its color, its streak is white or reddishbrown. H.=3.5-4. G.=3.9-4.2. Composition, Zn 67.0, S 33.0. Pyr. &c. B. P. Infusible. In O. F. it gives off sulphurous vapors and often a cadmium coating. The roasting is long and difficult, and after it, in the R. F. it gives a coat of Zn which is yellow when hot, and white when cold. Soluble in HCl. With f very little red vapor is given off, but much Ht S. It is also found in lamellar, imperfectly crystallized masses, which may have every variety of color. These masses are sometimes lamellar and sometimes saccharoidal. The dark varieties may sometimes resemble Garnet, Vesuvianite and Cassiterite, but its density about 4, and the blowpipe reactions distinguish it. When it is concretionary it is in spheroidal LECTURES ON MINERALOGY. 141 masses radiated and with a fibrous fracture. These masses may be large or small and show rings of color. The fracture,'where the masses are small, is usually compact. It might resemble in this state Barite, Celestite, Siderite or Apatite, but is easily distinguished by acids and the blowpipe. It is found also with an entirely compact fracture resulting from a partial decomposition of the saccharoidal variety. These generally show some scales, and their fracture and the blowpipe distinguishes them. Some of the dark varieties resemble Cassiterite, and certain kinds of Garnet, but it is distinguished both by its cleavage and hardness. It is one of the most abundant ores of zinc. It is found in many places in the U. S. FORMULAE OF THE CRYSTALS. Pt. XXV. 0 0 0 Fig. 16. -2-' — A-' Fg. 17. -2. co. Fig. 18. ooco. 00 02. Fig. 19. Two octahedra interpenetrating. Fig. 20 Twin crystal; composition-face 0. Fig. 21. coO, showing the twin plane. 303 Fig. 22. IHemitrope from the preceding. Fig. 23. co 0. 0. 303 coO c. Fig. 24. coO. 2; a characteristic form. Fig. 25. Hemitrope from the preceding. Fig. 26. - co 0, shortened in the direction of the diagonal of the faces. Fig. 27., The same, lengthened. Goslarite. An +'7 I1. ORTHORHOMBIC. SY. —White Vitriol, Zinc VitrioI, White Copperas, Zinc sulfate. Crystallizes as a right rhombic prism of 90~ 42'. It has a cleavage parallel to the macropinacoid. Lustre, vitreous. Transparent, translusent. Color, white, reddish or bluish. Streak, white. H1-=2-2.5. G.= 2.036. Composition, Zn 28.2, i 27.9, R 43.9. Pyr. &e. & B. P. In a closed tube yields water. Gives the reaction for zinc and sulphur; easily soluble in water. It is found as an efflorescence, or as an accidental product of decomposition of Sphalerite in certain mines. Smithsonite. 2n a. HEXAGONAL. SYN. —Dry-bone, Zinkspath, Kapnit. It is found in rhombohedra of 107~ 40', with a very easy rhombohedral cleavage, which gives it a lamellar structure. The crystals are sometimes the primitive rhombohedron and sometimes scalenohedra. In this last case, the crystals are usually very small and cover the amorphous variety. They are frequently covered with a coating which may be blackish or pure white. The rhombohedral crystals are usually much longer and have curved faces and a vitreous lustre, which is sometimes resinous, or even adamantine. Its fracture is uneven. Color, white, green, yellow or brown. Streak, white. H.=5. G.=4-4.5. Composition, Zn 64.8, C 35.2. Pyr. &c. B. P. In a closed tube loses C. Infusible. On Ch., with soda gives vapors which are yellow while hot, white when cold. It is soluble in acids with effervescence, which however is slow; the acid must be heated to produce it. 142 LECTURES ON MINERALOGY. It. is variously colored by foreign substances. In copper localities it is green. The blonde varieties are usually colored with iron or manganese. The stalactites, which are white, usually contain lime or magnesia. The concretionary masses have usually a stalactitic structure, occurring in little mamelons, sometimes covered with the points of crystals. Their lustre is generally feeble, but is sometimes vitreous. The fracture of these masses is sometimes lainellar or scaly, very rarely fibrous. They are sometimes compact and have the appearance of calcareous concretions. It is found amorphous and earthy, having the appearance of a coarse limestone, but its density and the blowpipe distinguish it. It is also found as a white arborescent, compact mass. It often resembles Siderite and the compounds of baryta and strontia, but is distinguished by the blowpipe. It is also distinguished from Sphalerite, Willemite and Calamine by its action with acids. It is much harder than any -of the carbonates, with which it might be confounded by its form and color. It is found in large quantities in Missouri, Iowa, Wisconsin and Tennessee. Hydrozincite. 2n 0+2 An If. SYS.-Zinc Bloom, Earthy Calamine, Zinkbliithe, Zinconise, Marionite. It is never crystallized. It is white and has a dull, earthy lustre. Sometimes when it has just been taken from the mine, it is translucent, but it quickly becomes opaque. It usually forms a series of white coatings, with vacant spaces between each bed, which is irregular and bent. It is sometimes found in balls, having the same disposition in concentric layers. Its streak is shining. lH.=2 - 2.5. G.=3.58-3.8. Composition, Zn 75.3, 0 13.6, H 11.1.l Pyr. &e. B. P. Heated in a tube, it gives off water and becomes yellow, but turns white again on cooling. It is reduced with soda on charcoal, the zinc is volatilized, burned and deposited as oxide. Acids dissolve it easily with effervescence. This mineral was formerly considered as an accidental product in other ores of zinc. Within a few years, however, it has been found in very large masses in Spain, and is a real mineral of zinc. It has been found in Pennsylvania, Wisconsin and Arkansas. TIN. Cassiterite. 9n. TETRAGONAL. SYN.-Tin Stone, Stream Tin, Zinnstein, Zinnerz, ]tain oxide. Simple crystals are usually rare, but are found with the forms, Pi, XXVI. Fig. 1-5. Generally the crystals are macled around a plane parallel to the octahedron of the second order, P 0o. This may take place bn the prism or on the octahedron. These macles show re-entrant angles and are often called tin beaks (becs d'etain.) Sometimes these macles occur several times, and give rise to geniculated crystals, iFgs. 9-11; The prisms are striated and cylindrical, while the faces of octahedra are smooth and polished. Each locality has forms peculiar to it, so that generally the crystals from the same place can be recognized by their form. Cassiterite is isomorphous with Rutile. It is trimorphous. If Sn is prepared in the laboratory by the action of water on the chloride or fluoride LECTURES ON MINERALOGY. 143 of tin, different forms are obtained according to the salt which is used. Both of these forms differ from the Cassiterite of nature. It has cleavages which are very, distinct, parallel to both prisms. The fracture is ordinarily unequal, sometimes conchoidal, rarely lamellar. Lustre, adamantine. Transparent, opaque. The colors of Cassiterite are very variable. It is found exceptionally colorless and transparent, in a few localities. Generally its color is every gradation, intermediate between blonde and black, owing to mixtures with iron. Sometimes, it is red, gray, white or yellow. The color is usually not equally diffused in the mass or the crystal, but is generally in bands. Streak, white, grayish or brownish. H1.=6-7. G.-6.4-7.1. Composition, Sn 78.67, O 21.23. Pye. &e. B. P. Infusible. In R. F., it is reduced with difficulty, but soda facilitates the reduction. With borax, it melts easily and the Yn becomes the base of an enamel. The glass is opaline and white, sometimes somewhat yellow when hot, on account of the presence of a little iron. It is only slightly acted upon by acids. It is also found concretionary in zones of different colors, but it is easily distinguished by its density, which is between 6 and 7; and its hardness distinguishes it from Sphalerite and Barite, which it frequently resembles. It is found in rolled pebbles with different bands of colors, and is then called Wood Tin. It is distinguished by its hardness and its density. It may become substituted by pseudomorphism for certain crystals, especially for those of Orthoclase, which are hemitrope and half interpenetrated and which are found in- the Trachytes. It is, however, only a kind of moulding, the cause of which is unknown. The Feldspar appears first to become clay, and the:clay to be replaced by tin, without any perceptible change in the form of the crystal. It is recognized by its density, which also distinguishes it from Vesuvianite, some varieties of Garnet and Tourmaline, which it frequently resembles in form, lustre and color.- From Sphalerite, it is distinguished by its blowpipe reactions and its hardness. It has been found in the U. S. at Lyme and Jackson, N. H. FORMULAE OF THE CRYSTALS. Pi. XXVI..Fg. 1. Co P. P; P sometimes predominates. Fig. 2. ooP. P. coP oo; also pyramidal as in Fig. 15. Fig. 3. The preceding, with Pco. Fig. 4. coP. ooP3. 3 P. P. Poo. Fig. 5. 3 Pz. P. CoP. Fig. 6. Fig. 1; showing the twin plane P oo. Fig. 7. Hemitrope from the preceding.'Fig. 8. The same, but with the plane in a different position. Fig. 9. Hemitrope of Fig. 3. Fig. 10. Hemitrope of Fig. 2. Fig. 11. Trilling, formed by the repetition of the hernitropy. Fig. 12. Twin of four individuals. Fig. 13. Iemitrope of a pyramidal crystal. Fig. 14. The same. Fig. 15. Hemitrope of a pyramidal crystal like Fig. 2. Fig 16. IHemitrope of nine individuals. Stannite.:2 (On, Fe, Zn,) S+Sn S'. SN. —Tin Pyrites, Bell Metal Ore, Zinnkies, Itain sulfure'. The composition of this substance in not very well defined; it appears to be a sulphostannide of iron and copper with a little zinc. It has been found very rarely with *traces of crystallization and of cleavage. Its 144 LECTURES ON MINERALOGY. lustre is metallic. Fracture, uneven. Opaque. Its color is steel-gray, iron-black or dark green, rather brownish from tarnish. Its streak is black. H.=4. G.=4.3-4.522. Composition, Sn 27.2, Cu 29.3, Fe 6.5, Zn 7.5, S 29.6. It is a very rare mineral, and has no resemblance to any other, except to the different Pyrites, from which it is distinguished by the action of nitric acid. TITANIUM, Rutile. i. TETRAGONAL. SYN.-Nigrine, Ilmenorutile, Titane oxyde'. Rutile is isomorphous with Cassiterite; it is crystallized in the same system and has the same relation to its modifications, and the same cleavages. It generally has a lamellar appearance. The simple crystals are sometimes octahedra, with plane faces and sometimes prisms which are striated and dull, also frequently macled. The crystals are like those of Cassiterite, showing geniculated forms, which are frequently turned in two or three directions, Figs. 2-7. The color varies from reddish-yellow to brown, always preserving a reddish tint; sometimes bluish, violet or green. In thin plates by reflection it is brownish blood-red, Its fracture is conchoidal across the crystal, and lamellar parallel to it. Lustre, metallic, adamantine. Translucent, opaque. H.=6-6.5. G.=4.18-4.25. Composition, Ti 61, 0 39. Pyr. &c. B. P. It is infusible and gives with fluxes the reactions for Ti. With borax and S.Ph., it dissolves, giving in the 0. F. a glass colorless when hot, and amethyst-violet when cold. It is not acted on by ordinary acids, but after fusion with alkaline carbonates, the acid solution boiled with tin foil gives a violet color. Besides its crystallized varieties, it is often found as a mass in a gangue and then somewhat resembles Vesuvianite. When the density cannot be taken into account, the color, the nature of the gangue and, if need be, a chemical examination will distinguish it. It is found in bacillary and acicular crystals; these may be fine needles enveloped in a gangue, which is often perfectly clear crystallized Quartz, which proves that the Quartz was formed after the Rutile and with sufficient slowness not to disarrange the general arrangement of the crystals. These acicular crystals are often very fine. Sometimes these crystals are reticulated on the surface of a gangue. In some localities, especially at Mt. Blanc in Dolomite, they affect a peculiar disposition. It is a kind of tissue of a yellowish changeable color made up of acicular crystals, which often show geniculations like the large crystals and are sometimes woven together. Under the name of Nigrine a black Rutile is described, which contains 14% of iron; it is never crystallized, but shows traces of cleavage. Its streak is yellowish-brown. Its infusibility distinguishes it from Tourmaline, Vesuvianite and Pyroxene. From Cassiteiite, by giving no metal with soda. It is found in verylarge crystals in Pennsylvania and Georgia. Titanic acid is found in nature in three different states and with three different forms. It is therefore trimorphous. In one of these forms it is isomorphous with Cassiterite, which under certain circumstances appears also to be trimorphous. Titanic acid is always found in one of these forms; two of which, Rutile and Octahedrite, are tetragonal, but with different dimensions. The third, Brookite, is orthorhomnbic. LECTURES ON MINERALOGY. 145 FORMULi OF THE CRYSTALS. P1. XXVII. -ig. 1 P.oo coP co. ooP3. P. Poo. P3. 3 Pa. Fig. 2. IHemitrope; composition-face P oo. Combination, co P. 3. P. Fig. 3.i Hemitrope, with two geniculations. Fig. 4. Twin crystal. Fig. 5. Twin, resembling an hexagonal prism and formed by the meeting of the extremities of the geniculated crystals. Fi. 6.- Hemitrope; composition-face P co. Fig. 7. Hemitrope. Octahedrite. Ti. TETRAGONAL. SYN.-Anatase, Dauphinite, Oisanite. The forms and dimensions of the, crystals are different from those of Rutile. It has an easy cleavage parallel to the base, and others more difficult, parallel to the octahedron. It is always crystallized. In crystals it shows two different types. From Dauphiny it is found in acute octahedra,- which sometimes show a base. These crystals are found on Dioryte, and are accompanied by Albite and Asbestus. From Brazil, however, the base predominates; the crystals are very much flattened, and show the octahedron and dioctahedron. Its colors are very variable. In Brazil, in certain diamond sands; it is found almost colorless or pale honey-yellow; sometimes it is reddish-brown, but generally it is a characteristic dark brown, which is quite distinctive. It is greenishyellow by transmitted light. In thin scales it is transparent. It is the most refringent of bodies, after the sulphate of mercury, so that its lustre is very bright. The lustre is often hidden in rolled crystals. Its fracture is lamellar or conchoidal across the crystals. Lustre, metallic or adamantine. Transparent, opaque. Streak, colorless. Its chemical characters are that of Rutile. Its density which is less, becomes the same as Rutile, on being heated. ][.=4-5.5. G.=3.82-3.95, or 4.11-4.16 after heating. Composition, Ti, 61, 0 39. fPr. &e. B. P. Same as Rutile. It has been found at Smith — field, R. I. FORMULA: OF THE CRYSTALS. Pt. XXVII. Fig. 8. P. Fig. 9. P. OP. Fig. 10. P. OP. Fig. 1I1. PO. PP5. Fig. 12. P. UP. 2Poo. Fig. 13. P. OP. P oo. coP co.. Fig. 14. OP. P. Poo. 2Poo. Brookite. T'i. ORT0ORHOMBIC. Syt.- Arkansite. It is much rarer than Rutile. It is ordinarily found in thin plates,. which are to be referred to the right rhombic prism of 99? 50'Y Thecrystals are complex. The faces of the macropinacoid are striated andi dull, the others are smooth and lustrous. There is an indistinct cleavage' parallel to the base and prism. Transparent, opaque. Lustre,; metallic,. adamantine. Color, brown, yellowish or reddish. Streak. colorless, gray — ish or yellowish. Hi.=5.5-6. G.=4.12-4.23. Composition, Ti 61.0,. 0 39.0. Pyr. &c. B. ]P. Same as Rutile. The hardness is less than' Rutile, as is also the density, which however becomes the same: on heat-, 10 146 LECTURES ON MINERALOGY. ing. It is found at Magnet Cove, Arkansas, and at Ellenville, Orange CO., N. Y. FORMULAE OF THE CRYSTALS. P1. XXVII. Fig. 15. o P. oo P oo. P2; the usual form of Arkansite. Fig. 16. The same, with o P co predominating. Fig. 17. co P. o P oo o P. 00 Poo 2. P. iP. 2 P. P 2. 2P2. J- P co. iPco. 2Pco.* OP; from the Urals. Fig. 18. o P. c P oo. o P mc. o P 2. P. jP. P'2. 2P2. ~Poo. PPco. 2P co. OP; from Ellenville: N.Y. LEAD. Lead. Pb. ISOMETRIC. SYN.-Gediegen Blei, Plomb natif. It has been found in several localities, but is however an accidental product, which is exceedingly rare. It has been found as globules in Galenite, as filaments or sheets in lava or basalt, or formed by reducing agencies on either the sulphide, sulphate or carbonate of lead. When it is found on the outcrops, as in S. A., it is probably owing to fires having been kindled upon the vein. It is crystalline, and shows its system to be isometric. Its lustre is metallic. Color, lead-gray; malleable and ductile. f.=1.5. G.- 11.445. Pyr. &e. B. P. Fuses easily in the 0. F., covering the Ch. with a yellow coating; in the R. F. volatilizes. 9iniuml. +b-2 Pb. SYN.-Mennig, Plomb oxide rouge. In many localities oxides of lead are found as products of the decomposition of Galenite or Cerussite. It is always found as a pulverulent coating, on the surface of other ores. Lustre, greasy or dull. Opaque. Color, very variable; it is yellow when its composition is near Massicot and redder when it approaches Minium; generally it is orange-yellow, which is more or less dark. Streak, orange-yellow. H-.=2.3. G.=4.6. Compostion, Pb 90.66, 0 9.34. Pyr. &e. B. P. In the R. F. easily reduced to metallic lead. Its most distinguishing character is its color and association with the other ores of lead. Galenite. Pb S. ISOMETRIC. SYN.-Galena, Bleiglanz, Bleischweif, Plomb sulfure. It is by far the most important of the ores of lead, the other minerals being frequently nothing but the products of its alteration. It has a perfect cleavage in three directions at right angles to each other, all equally easy. It is usually found crystalline or crystallized; the crystals are often very large, the dominant forms being the cube, rhombic dodecahedron and octahedron. The general form is the cube and octahedron. The crystals are sometimes macled and are usually the cube, macled by hemitropy around a normal to the face of the octahedron. More frequently it is found as crystalline masses made up by the union of several crystals. The hemitropy of the cube is frequently found in these masses and is recognised by LECTURES ON MINERALOGY. 147 the cleavage, which shows two systems of cubes. It sometimes has a peculiar look, which is owing to a slight inclination of two systems of crystals, showing a slight depression between the two. It is also found in comby masses, formed by a large number of little crystals. Its fracture is ordinarily lamellar or saccharoidal, passing sometimes to a granular texture. In some particular varieties it is entirely compact, with a smooth, con&cloidal fracture, showing concentric zones like some specimens of Silex. It has a grayish-blue color. In its fresh fracture it has a metallic lustre, which is quite bright, but becomes dull on exposure. Streak, lead-gray. 11.=2.5-2.75. G.=7.25-7.77. Composition, Pb 86.6, S 13.4. Pyr. &c.'B. lP. In an open tube gives off S. On Ch., decrepitates, and then in O. F. is roasted, giving off a sulphurous odor and lead fumes, which coat the coal at a short distance from the assay with a yellow ring. After being roasted, it gives metallic lead which is malleable. It is soluble in acids, giving off HS. It usually occurs in lamellar or saccharoidal masses, in which way it occurs in nearly all the lead mines. It is usually found disseminated in Calcite, Quartz, Fluorite or Barite. The lamellae of these masses are usually small, sometimes plane, sometimes curved, and it can usually be seer that they are all arranged in the same general direction. Sometimes these masses appear to be stratified. When the mineral is quite compact its color is much bluer. It is frequently found pseudomorphic, replacing crystals of other substances. The most usual pseudomorph is after Pyromorphite. Galenite is the simple. sulphide of lead, but is rarely ever pure. It alloys itself by mixture with a certain proportion of sulphide of silver, which is isomorphous with it. There is probably no specimen of Galenite, which does not contain some silver. In some ores the proportion is veryslight, while in.others it is sufficiently large to make it an ore of silver. It is possible to a certain extent, to judge from external characters whether the ore is rich in silver or not, but these characters are only true within certain limits, and, if reliance is placed on them exclusively, very grave errors will be committed. In every case, recourse must be had to an assay for silver, in order to obtain a clear, or even approximate idea of the yield of art ore. The Galenites with large lamella, and especially those which are well crystallized, are generally poor in silver. Those which show an arborescent structure are often argentiferous. Those with small lamelle, especially when their faces are curved, and have a granular fracture, and which are nearly compact and of a dark blue color, are generally rich in silver. The ones which are entirely -compact, although they differ but little from those described, are rarely rich, but usually, very poor. In the stratified Galenites, the glass usually shows parts which are lamellar and bluish, having the aspect of ordinary Galenite, but near tk which there is a cement which is entirely compact and of a much whiter color. These parts are not Galenite, but a mineral which has about the same relation to lead, which Tetrahedrite bears to copper. It is composed principally of As, Sb, Pb, and other metals, and is always more or less argentiterous and is sometimes very rich. On account of its lamellar structure, Galenite might be sometimes mistaken for Stibnite, but is distinguished by being harder and less brittle, and by its cleavage in 3 directions, while Stibnite has only one; the blowpipe also distinguishes it. It sometimes resembles Tetrahedrite, but is distinguished by its cleavage and by the absence of copper. At 148 LECTURES ON MINERALOGY. first- sight, Mlolybdenite resembles Galenite, but is much softer, and lamellar in one direction only. Its lamellme are flexible. Galenite is the most important ore of lead. It is sometimes used for glazing earthenware. It is found abundantly in the U. S., in Missouri, Illinois, Wisconsin, and also to some extent in N. Y. State, but the mines have not generally proved profitable. It has been found in many other states, particularly in N. C. But little of the Galenite of the eastern part of the U. S. is argentiferous. Some of the veins of the other states contain enough silver to pay for extraction. FORMULAE OF THE CRYSTALS. Pi. XXVII Fig. 19. ooOoo. O; the most usual form. Fig. 20. The same, with the faces equally developed P1. XXVIII. Fig 1. co O oo. o 0. Fig 2. coO co. oo0. 0. Fig. 3. The preceding, with the faces of the octahedron larger; a characteristic form. Tig. 4. oo 0 oo. cc 0. 0. 30X-. Fiy. 5. oo oo. 20. Fig. 6. 0. oO coo. coO. 20; also characteristic. Fig. 7. Twin crystal; composition-face 0, and flattened parallel to the same. Bournonite. 3 (Cn, Pb) S+Sb2 S3. ORTHORHOMBIC; SYN.-Wheel Ore, Ridelerz, Schwarzspiessglaserz, Antimoine sulfure plumbo-cuprifere. The primitive form is a right'rhombic prism of 93~ 40'. It has an imperfect cleavage parallel to the brachypinacoid. This is probably not a cleavage, but a separation of the different crystals. The simple crystals have two types, according as the dominant, form is the prism or made up of the pinacoids, but such crystals of Bournonite are rare, as it is almost always found as macled crystals. Sometimes the made is formed of two crystals only, but there are generally a large number of simple crystals arranged in a perfectly characteristic manner, somewhat resembling a cog wheel or pinion. In Brazil it is found in large crystals which have no lustre, but-the surface of which is covered with points. It is also found in compact masses which appear to be parts of large crystals, that have been prevented from being developed. These can be easily distinguished by- their fracture and peculiar lustre; They are covered in some specimens with blue or green spots, resulting from a superficial decomposition of the copper. It has a conchoidal fracture, which is usually smooth. Its lustre is metallic, and is very bright on the natural faces when they are smooth. Upon the fracture the lustre is somewhat resinous, without ceasing to be metallic; this, with the nature of the fracture, characterizes the mineral. Its color and streak are gray, varying from iron to steel-gray. It is very brittle. H.=2.5-3. G.=5.7-5.9. Composition, Pb 42.4, Cu 12.9, Sb 25, S 19.7. Pyr, &c. B. P. In a closed tube, decrepitates and gives a dark red sublimate. On Ch., it is fusible and gives off Sb, which is condensed in a white ring. In the 0. F., there is formed a yellow ring of Pb, and beyond that the antimony coat appears. In the R. F., a globule of copper is obtained, which is brittle. There is usually an odor of arsenic. Decomposed by nitric acid. It resembles Tetrahedrite, but can be distinguished from it by the presence of lead. LECTURES ON MINERALOGY. 149 FORMULAE OF THE CRYSTALS. Pl. XXVIII. Fig. 8. OP. o Poo. P. oo. Fig. 9. OP. ooP. oPoo. co0 P. Poe. P oe. Fig. 10. oo oo. OP. Poo. oePoe. ooP; lengthened in the direction of the brachydiagonal. Fig. 11. o P oo. oioP o. OP. P. ~P. coP. ooP2. ooP2. P oo. ~Poo. Poo. Fig. 12. Twin crystal; composition-face co P. Fig 13. Wheel-shaped crystal, formed by repeated twinning. Anglesite. Pb S. ORTHORHOMBIC. SYN.-Bleivitriol, Vitriolbleierz, Plomb sulfate'. It is isomorphous with Barite and Celestite. The primitive form is a right rhombic prism of 103~ 43', while that of the other minerals is 104~ and 106'. It has a very easy cleavage parallel to the base, anid two others parallel to the faces of the prism. Its crystalline forms are nearly the same as those of Barite. It occurs also in a combination of the rhombic octahedron and the prism, in which the octahedron always predominates. It is also found macled. The fracture is lamellar or conchoidal. Lustroe, adamantine, vitreous and resinous. Transparent, translucent, opaque. It is generally white, but sometimes black on the surface, or tinged with yellow, green or blue. H.=2.75-3, G-.=6.12-6.39. Composition, Pb 73 6, 8 26.4. Pyr. &c. B. P. Decrepitates and fuses in the flame of a candle. In the O. F., decrepitates and melts to a transparent bead, which becomes opaque fon cooling. In the R. F., intumesces and then gives the reactions for lead, a metallic globule and yellow ring. Concentrated.: dissolves it completely. Soluble in 22,816 parts of water. It is also found in lamellar masses, which can be recognized by their density, which is about 6, and their adamantine lustre; also in earthy masses, which are often either concretionary, or made up of beds fitting into each other. Such masses must be distinguished by their blowpipe characters. Its exterior characters ally it with Cerussite, but it is easily distinguished by the action of acids. It can be distinguished from all other minerals by its reactions for Pb and S. It is found associated with Galenite. The most celebrated locality in the U. S.was formerly Phenixville, Pa. FORMULA OF THE CRYSTALS. P1. XXVIII. Fig. 14. ooP2. P o. Fig. 15. oo P 2. Poe. oe P o. fg. 16. The preceding, with P and P oo. Fig. 17. P; from Phenixville. Fig. 18., P. oP. PFig. 19. c aP. Poo. Po., P. 2. co P o. 0o P 00. Clausthalite. Pb Se. ISOMETRIC. SYN.-Selenblei, Plomb s6leniure'. It is a selenium Galenite. Nothing in its external characteristics distinguishes it from the latter, with which it is associated in a very small number of metallic deposits. It has the same cleavage and is found in 150 LECTURES ON MINERALOGY. lamellar masses, which have either large lamellae, or are saccharoidal or even granular; detached crystals have not yet been found. Cleavage, cubic. Fracture, granular or shining. Lustre, metallic. Opaque. Color leadgray, distinctly bluish. Streak, darker than color. H.=2.5-3. G.=-7.6-8.8. Composition, Pb 72.4, Se 27.6. Pyr. &c. B. P. In a closed tube, it decrepitates. In an open tube, gives the odor of selenium. On Ch., fuses readily and gives a strong odor of selenium, coating the coal near the assay gray, with a reddish border (Se), and beyond this yellow (Pb). If pure, it is extremely volatile. The distinctive character is its blue color, which approaches to black; but this character is a very delicate one and is difficult to appreciate. In reality the external aspect cannot determine it and it is indispensable, when the presence of this mineral is suspected, to test it. This test is a simple treatment before the blowpipe, which in the presence of selenium affords a strong and unpleasant odor. Pyromorphite. 3 Pb13 T+Pb C1. HIIEXAGONAL. SYN.-Phosphate of Lead, Griinbleierz, Plomb phosphate'. Its usual form is the hexagonal prism, with traces of a cleavage parallel to the prism and pyramid. Itis generally crystallized as an hexagonal prism, which may have a variable number of faces on the edge of the base..These crystals are often distorted by the rounding of their faces, or by having the base hollow as in the crystals from Phenixville, Pa. The gray or colorless varieties, which are nearly pure, are often found in large striated and rounded crystals. The yellow varieties, which contain is, are generally quite regular. They are, however, somewhat rounded at times. The green varieties are usually in small distinct crystals, but are sometimes barrel-shaped. This rounding takes place on the vertical faces only and does not affect the base. In the orange-red varieties, the rounding of the vertical faces is even more distinct, so that the crystals are sometimes almost spheroidal. This, with their color, almost distinguishes them. The fracture is conchoidal and smooth. Lustre, resinous. Translucent, opaque. The colors are very variable, green, yellow, brown or white, and are dependent upon the composition.. The varieties which are nearly pure phosphate of lead, are generally colorless or grayish, with a slight yellowish -tinge. When they have a color which is more or less green, it is usually owing to the presence of copper or chromium. The varieties which contain considerable Xs are yellow. All of these varieties may occur together, so that the color is intermediate between gray, green and yellow, and is sometimes very undecided. In some localities it is found with a dark orange-red-color, which is probably owing to the presence of chromic or vanadic acid. Whatever may be the color, it has a peculiar lustre which is partly adamantine, and partly resinous. Streak, white, sometimes yellowisdh. 1.=3.5-4.5. G.=6.5-7.1. Composition, Pb 74.1, P 15.7, C1 2.6, Pb 7.6. P and Xs being isomorphous, small quantities of the latter are often found in the crystals. Some varieties contain also copper, vanadium and chromium, without its being possible to make a separate species of them. Lime occurs also in small proportions. Dyer. & c. B1. P. In a closed tube gives a white sublimate of' chloride of lead and As if the latter is present. Fuses at 1.5. In the R F., it gives a globule of lead which is brittle; in the 0. F., melts and gives a LECTURES ON MINERALOGY. 151 globule, which in cooling assumes polyhedric forms. This a characteristic peculiarity. Soluble in acids with difficulty, but without residue. Besides these forms, it is often found in bacillary fibers which are often interlaced. These crystals are often dark and look very much like moss, this is especially true of the green varieties. It is also found in mamelonated masses with a velvety lustre, owing to the little crystals which appear on the surface. It is also found in concretionary masses of different colors. These masses are characterized by their lustre, which is feeble but at the same time adamantine and resinous, the latter predominating. It is also found in amorphous masses, which sometimes appear to be intermediate between compact and concretionary. They are crystalline masses made up of large crystals, which have been prevented friom being developed. This is shown by the acicular crystals which are seen at a few points at the same time. These masses are very much like Anglesite and Cerussite, but their lustre is much less resinous, and their chemical characters are different, both with the action of acids and before the blowpipe. It sometimes occurs in red gummy-looking drops, when it contains vanadic acid. It is a valuble ore of lead. It was formerly found in great abundance in the Wheatley Mine, Pa., and in the Davidsbn Mine, N. C. FORMUL2E OF THE CRYSTALS. P. XXVIII. Fig. 20.' coP. 0P; most usual form. Pjig. 21. 0P. coP. ooP2, lig. 22. ooP. OP. P. Fig. 23. ooP. 0P. P. ooP2.!Nimletite. 3: Pb' Xs+Pb C1. HEXAGONAL. SYN.-Campylite, Mimetine, Mimetisite, Plomb arseniat6. It is generally found- crystallized as an hexagonal prism, with a number of pyramids. Cleavage imperfect, parallel to the pyramid. Lustre, resinous. Translucent, opaque. Color, pale yellow, orange-yellow, brown or white. Streak, white. H.=3.5. G.=7-7.25. Composition, Pb Xs 90.60, Pb Cl 9.34. Pyr. &C. B. P. In a closed tube, gives vapors of chloride of lead and of arsenic. Fuses at 1, and in the R. F. gives a globule of lead, the usual lead coating and often a white one of chloride of lead. Soluble in 1~. It resembles Pyromorphite in form and association, and it is sometimes difficult to distinguish between the two species, especially when Pyromorphite contains arsenic. It is often botryoidal and compact. It is a rare mineral and was formerly found at Phenixville, Pa., associated with Pyromorphite. When found in large quantities, it is a valuable ore of lead. FORMULX OF TIlE CRYSTALS. Pl. XXVIII. Fig. 22. coP. OP. P; usual form. Fig. 24. coP. OP. 2P. PI. XXIX. Fig. 1.P. P. 2P. FiP. 2P. g. 2. ooP. P. Fig. 3. ooP. P. 2P. Fig. 4. P.'OP. -152 LECTURES ON MINERALOGY. Cerussite. Pb 0. ORTHORHOMBIC. Sys. —Carbonate of Lead, Weissbleierz, Plomb carbonate, Plomb blanche, Ceruse. It is isomorphous with Witherite, Strontianite and Aragonite, with which it is sometimes associated. The angle of the prism is 117~ 13'. There is a trace of cleavage parallel to the prism, which gives the mineral at times a lamellar appearance. The simple crystals have the same form as those of Aragonite. There is a form which is very much flattened, in the direction of the brachypinacoid, P1. XXIX. Fig. 7. This form is peculiar to certain crystalline masses, made up of acicular crystals woven together, sometimes parallel to each other, sometimes divergent or even interlaced without any apparent law. These Imasses. are generally milkwhite and without lustre, or with a silky lustre, the crystals themselves being often made up of little capillary crystals. Besides these simple forms, there are macles, which are generally hemitropes around the face of the prism. If this made is repeated several times, it gives the star-shaped twin, Fig. 13, but it is sometimes much more complex. As the angle is almost 120~, the interior opening being very small and generally full of massive Cerussite, there results a regular star with six branches. It is very brittle. Fracture, conchoidal. Lustre, adamantine. Transparent, translucent, opaque. Its colors are white, grayish-white and yellowishwhite, blue or green. It is sometimes black on the surface, but this is superficial, being caused by sulphurous vapor, and does not interfere with the adamantine lustre. II.=3-3.5. G.=6.465-6.48. Composition, Pb 83.5, C 16.5. Pyr. &c. B. P. In a closed tube decrepitates, and seems to pass into a state of dimorphism similar to that which takes place with Aragonite. After decrepitation, it becomes reduced in the R. F. to a metallic globule. Soluble with effervescence in dilute 1. It is fiiequently found in saccharoidal masses, which are easily distinguished by their adamantine lustre and their density, which is about 6. Amorphous and earthy masses are also found. which are only characterized by their great density. They are colored differently, according to their association. It resembles Anglesite, but is distinguished by the action of acids. It is a valuable ore of lead. It was formerly found in large crystals at the Davidson Mine, N. C., and at Phenixville, Pa., and is generally found on the outcrops of veins. FORMULAE OF THE CRYSTALS. P. XXIX. Fig. 5. P. 2 P oo; resembles an hexagonal pyramid. Fig. 6. P. oo P ccoo. 2 P oo. c P; the faces 2P co and oo P oo usually have horizontal striations. Fig. 7. oc P oo. P. oo P. oo P 3; tabular crystal. Fig. 8. oo P o. 4 P oo. 2 P o. P. oo P..Fig. 9. P Oc. OccP o. P. oP. ooP3. ooPco. Fig. 10. ocP. ooPco. 0P. P. 2Poo. 3Poo. 4Poo. Fig. 11. ooP. OPT. oP. 2Pc. 4P c. P. ooP. oz P c. cP 3. P. Fig. 12. Twin crystal, with the combination P co. 2 P Wc. co Pcc. P. oo P: composition-face oo P. Fig. 13. Trilling, with the combination X P oc. ac P. P. i P 1o. Fig. 14. Twin crystal, with the form of Fig. 7. Fig. 15. Horizontal projection of a twin crystal. Fig. 16. Trilling, with the form of Fig. 7. LECTURES ON MINERALOGY. 153 Crocoite. Pb jr. MONOCLINIC. SYN.-Crocoisite, Rothbleierz, Plomb chromate'. It crystallizes as an oblique rhombic prism of 93~ 42'. It has several cleavages, one. parallel to the prism distinct, the other parallel to the base and clinopinacoid less so; but these cleavages are difficult and as the substance is very fragile it is not easy to determine them. It is always in more or less perfect crystals, which are generally attached to a gangue and form a crust upon it. Its fracture is conchoidal. Lustre, adamantine, vitreous. Translucent. It is very brittle. Its color is dark redsomewhat like that of Realgar, which, however, contains more yellow. Streak, orange-yellow. HI.=2.5-3. G.=5.9-6.1. Composition, Pb 68.9, Cr 311.1. Pyr. &c. B. P. In a closed tube decrepitates and blackens, but recovers its color on cooling. Fuses at 1.5, spreads over the charcoal and gives in the R. F. a metallic globule, a chrome scoria and lead fumes. It is easily dissolved in acids, and in HCl gives a green solution and crystallized needles of chloride of lead. FORMULAE OF THE CRYSTALS. Pl. XXIX. Fig. 17. coP. -P. P; both hemipyramids are equally developed. Fig. 18. oc P. -P. Fig. 19. The preceding, with oc P2. Fig. 20. coP. 4 P oo; Beresowsk. Fig. 21. coP. -P. 4 P coo. Fig.22. co P. co P 2. coP bo. -P. P oo. 3 P o. 2 P 2. O P. Fig. 23. coP. -P. Poo. 2 P2. OP. 2P co. Pcc. Pco. Fig. 24. ooP2. -P. 3 Poo. 4 P o. ooP. Stolzite. Pb'W. TETRAGONAL. SYN.-Tungstate of Lead, Scheelbleispath, Wolframbleierz, Scheelitine. It is isomorphous with Wulfenite and is found under the same conditions. Its crystals are never flattened, but show the octahedron distinctly. It has an imperfect cleavage parallel to the base. Lustre, resinous. Translucent, opaque. Color, brown, red, green or yellowish-gray. Streak, colorless. HI.- =2.75-3. G.=7.87-8.13. Composition, Pb 49, W 51. Pyr. &e. B. P. It decrepitates and fuses at 2 to a crystalline bead. In the R. F. on Ch., it gives a metallic globule. Affords the reactions for tungstic acid and lead. Decomposed by 1, giving a yellow residue of tungstic acid. It is of a much browner color than Scheelite, but generally the two species must be distinguished by trial. It has been found in this country at Southhampton, Mass. FORMULAE OF THE CRYSTALS. PI. XXIX. Fig. 25. P. ooP. Fig. 26. P. 2P. ooP. Poc. Wulfenite. Pb Mo. TETRAGONAL. SYN. —Mfolybdate of Lead, Gelbbleierz, Plomb molybdate, Melinose. It has an, easy cleavage parallel to the octahedron, and a less easy one parallel to the base. The crystals are usually very short resembling'square 154 LECTURES ON MINERALOGY. tablets, and have faces of an octahedron of the second order, which are rarely carried to a point. They are usually set on their edge on a gangue, the base having generally less lustre than the other faces. Sometimes the crystals are thicker, opaque and without lustre. They have always about the same form, and rest on the gangue in the same way. Exceptionally it is found with an octahedral form; they are usually small, and of a dark orange color. This variety always contains chromic acid. Its fracture is subconchoidal and without lustre, even when the natural faces are brilliant. Its lustre on the natural faces is resinous or adamantine, sometimes prominent and sometimes feeble, as it is often covered with a yellow powder. Translucent, opaque. Its color is yellow, with different shades; sometimes it is almost canary-yellow, sometimes orange-yellow, which is probably owing to the presence of a little chromic acid. When it contains tungstic acid it is brownish-yellow; it is also gray or white. Streak, white. 1i.=2.75-3. G.=6.05-7.01. Composition, Pb 61.5, io 38.5. Pyr. &e. B. P. It decrepitates and becomes dark-brownish yellow, and fuses at 2. On Ch., melts, and gives a metallic globule and scoria. Affords the reactions for lead and molybdic acid. Decomposed on evaporation in HC1. It is also found in crystalline masses, made up of lamellse which are interlaced; these masses are cavernous, being made up of crystals which have left considerable spaces between them, thus diminishing the density of the mass, which should be about 7. The masses become at times entirely compact, and show no traces of crystalline structure. It has been found in this country at Southampton, Mass., and at PhenixVille, Pa. FORMULA OF THE CRYSTALS. Pl. XX. Jig. 1. P. coP. 0P. Fig. 2. oo P. OP P. P.Fig. 3. OP. ooP2.:.P. coP. Fig.4. PPo. ~P. Fig. 5. 0P. coP. ooP2. Fig. 6. 0P. P. ~P. Fig. 7. P o. UPoo. P. ~P. Fig. 8. OP. jP. Poo. Fig. 9. ooP o. OP. ~ P; Phenixville. All the compounds of lead containing oxygen, appear to have been formed by the action of outside agents upon Galenite. They are usually found in the vein within the influence of surface waters, which at lower depths contains sulphides only. Thus, Stolzite and Wulfenite are found at Bleiberg in Carinthia, on the outcrop of a vein of Galenite, which is crossed by a vein containing Molybdenite and Wolframite. The occurrence of Anglesite, Cerussite, Pyromorphite and Mimetite is similar, although these minerals are more common. It is quite common to find pseudomorphs of all the oxidized minerals into sulphides or vice versa. All of the oxides of the metals, are usually found within surface influences, the sulphides below being unaltered. BISMIUTH. Bismuth. Bi. HEXAAGONAL. SYN.-Gediegen Wismut, Bismuth natif. It crystallizes as a rhombohedron of 87~ 40'. It is isomorphous with Antimony, having the same cleavage parallel to the face of the rhombo LECTURES ON MINERALOGY. 155 hedron and the base, which gives it the appearance of having a lamellar fracture. Lustre, metallic. Opaque. Color, silver-white, with a reddish tinge. It is subject to tarnish. Streak, same as color. Sectile. When cold it is brittle, but slightly malleable when heated. 1I.=2-2.5. G.=9.727. Composition, when pure, Bi. Pyr. &c. B.. P. It melts in the flame of a candle. On Ch., fuses and is entirely volatilized, leaving a yellow coating. It is not attacked by HC1. It is soluble in 8, from which it is precipitated by diluting the solution with water. It is sometimes found in large masses, but is usually disseminated in a gangue. It has a definite position, all of the cleavages have the same direction, and most of the specimens look alike. The direction of the lamellm can be seen on almost every specimen. It usually occurs in reticulated masses scattered through a gangue.: It has a rosy tinge which makes it resemble Linnmeite and Cobaltite, but it is distinguished by its lamellar fracture and by its being completely volatile. It has been found in small quantities at Lane's mine, Connecticut, and in S. Carolina. Bismnuthinite. Bi? SS. ORTHORHOMBIC. SYN.-Bismuth Glance, Wismutglanz, Bismutline, Bismuth sulfure, It crystallizes as a right rhombic prism of 91~ 30'. The crystals are * always acicular. It has easy cleavages parallel to the brachypinacoid and base, and a less easy one parallel to the macropinacoid. Lustre, metallic. Opaque. Color, lead-gray or tin-white, with a yellowish or iridescent tarnish. Streak, same as color. II.=2 G. =G.-6.4-7.2. Composition, Bi 81.25, S 18.75. Pyr. &c. B. P. -In an open tube, gives sulphurous fumes and a bismuth sublimate. On Ch., fuses at 1 into drops, brown while hot and yellow on cooling, coating the charcoal. Dissolves in f and gives a precipitate on dilution. It is sometimes found massive, with a foliated or reticulated structure. It is also found associated with Native Bismuth and sometimes in large masses like Stibnite, with which it is isomorphous, having the same easy cleavage parallel to the brachypinacoid. It has the same general characters also, except that the crystals are usually much smaller,. It was probably much less soluble in the solutions from which it crystallized than Stibnite. Its color too is much darker, and it is sometimes variegated. It cannot generally be distinguished from Stibnite except by the blowpipe or by dissolving it in S, which does not act on Stibnite. It has been found in Haddam, Ct., and in N. Carolina. Aikinite. 3 (eu, Pb) S+3Bia S3. ORTHORHOMBIC. SYN.-Acicular Bismuth, Aciculite, Nadelerz, Bismuth sulfure plumbocuprif3re. It crystallizes as a right rhombic prism of 1100. The crystals are usually long and acicular, which gave it the name of Needle Ore, and are generally imbedded in a gangue. Fracture, uneven. Lustre, metallice Opaque. Color, lead-gray slightly red. ]I.=2-2.5. G.-=6.1-6.8. Composition; Bi 36.2, Pb 36.1, Cu 11, S 16.7. Pyr. &c. B. P. In an open tube, gives sulphurous fumes and a 156 LECTURES ON MINERALOGY. bismuth sublimate. On Ch., fuses and gives the bismuth and lead coatings. With fluxes, the reactions for copper. Decomposed by u. It has been found in the U. S. in North Carolina and Georgia, and is often associated with Gold. Tetradymite. Bi2 Te3. HEXAGONAL. SYN.-Telluric Bismuth, Tellurwismutj Bismuth tellur6. It is found in small crystals which are often tabular. They generally show faces of a rhombohedron of 81~ 2' and frequently the base, and are usually macled. Cleavage easy, parallel to the base. Lustre, metallic and very bright. Color, pale steel-gray. The lamine are flexible and soil paper. IH.=1.5-2. G.=7.2-7.9. Composition variable, as it often contains sulphur and selenium; for the formula Bi2 Te3, Bi 51.9, Te 41.1. Pyr. &. B..P. In an open tube, gives a white sublimate of tellurous acid. On Ch., fuses and gives a white sublimate. In the R. F., tinges the flame bluish-green. It has been found in the U. S. in the gold mines of Virginia, N. Carolina and Georgia. FORMULAE OF THE CRYSTALS. Pi. XXX. Fig. 10. Twin, consisting of four individuals; composition-face R; 3 R. OR. ARSENIC. Arsenic. As. HEXAGONAL. SYN.-Gediegen Arsen, Arsenic natif. It crystallizes as a rhombehedron of 85~ 41'. It has an imperfect cleavage, parallel to the base. The crystals are rare and are very small rhombohedra. The fracture is granular, and sometimes saccharoidal and even conchoidal. Lustre, almost metallic. On a fresh fracture, which is often very brilliant, it is steel-gray or tin-white. It afterwards tarnishes and becomes dark gray or black. Streak, same as color. H.=3.5. G.=5.93. Composition, when pure, As. Pyr. &e. B. P. Gives metallic arsenic in a closed, and Xs in an open tube. In the R. F., it volatilizes without residue and without melting, coloring the flame blue. It is not attacked by HCI, but is soluble in f. It can often be easily detached in plates, with curved surfaces which fit into each other. The mainelons are generally large, and are covered with points of crystals. It is also found in bacillary masses as little irregular prisms, generally in a gangue of Quartz or Barite. It is also found as concretionary masses in little mamelons, which have been deposited on the salient points of different minerals, often on Rhodochrosite. This mamelonated character distinguishes it from Nagyagite or Hauerite, with which it is often associated. It has been found in the U. S. at Haverhill and Jackson, N. H., and at Greenwood, Me. Arsenolite. Xs. ISOMETRIC. SYN.-Arsenous acid. Arsenige Sdure, Arsenikblithe, Arsenit, Arsenic oxide'. It is found rarely in little octahedral crystals, or as silky tufts on the LECTURES ON MINERALOGY. 157 sides of a fissure. It is generally found as a white, earthy powder, associated with Arsenic. It is probably dimorphous with Senarmontite. It is sometimes found botryoidal, stalactitic and earthy. Lustre, vitreous or silky. Transparent, opaque. Color, white, with a yellowish or reddish tinge, owing to impurities. Streak, same as color. Taste, astringent. 1i.=1.5. G.=3.698. Composition, As 75.76, 0 24.24. Pyr. &c. B. P. Sublimes in a closed tube. On Ch., is entirely volatile, giving white fumes and a garlic odor. Slightly soluble in hot water. It has no other characters, than its association and chemical reactions. iRealgar. As S. MoNOCLINIc. SYN.-Rothe Arsenblende, Roth Rauschgelb, Arsenic sulfur6 rouge. It crystallizes as an inclined rhombic prism of 74' 26'. It is always crystallized or crystalline. The crystals usually have a very large nnmber of faces, but the primitive form is comparatively rare. The usual faces are shown in P1. XXX. Figs. 11-14. It has an easy cleavage, parallel to the base and clinopinacoid, and a less easy one parallel to the orthopinacoid. It fracture is smooth and conchoidal, with a resinous lustre. The lustre is bright on the natural faces which have not been altered. Transparent, translucent, opaque. The color is a characteristic red. When it has been exposed to the light for a long time, it becomes orange-yellow. Streak, red when not decomposed, but generally orange-yellow. H.=1.5-2. G.=3.4-3.6. Composition, As 70.1, S 29.9. Pyr. &c. B. P. In a closed tube, it fuses and volatilizes without decomposition. The vapor is condensed in an orange-colored sublimate, which is also fusible and volatile. In an open tube, it burns with an odor of sulphur and arsenic. It is soluble in caustic alkalies. In collectionS it must be kept from the light and as much as possible from the air, otherwise it becomes decomposed and falls to powder. Realgar can usually be distinguished by its color, streak and hardness, and its-association with Native Arsenic, and if necessary by its chemical characters. The only substances which resemble it are Crocoite and Cinnabar. The color of the streak of Crocoite is yellow and its association is different. The blowpipe characters, streak, and chemical reactions distinguish it from Cinnabar. FORMUL2E OF THE CRYSTALS. P,. XXX. Fig. 11. ooP. ooP2. 0P. Pcoo, Fig. 12. The preceding, with P and c. Fig. 13. ooP. cP 2. co P 4. P o. ooP 2. o0PCo. P. OP. -P co. Poo. 2Pco. Poo. 2Pcc. PI2. 2P2. 4P2. Fig. 14. ooP. OP. UP. oo P 2. ooPo. ooP. P oo, 2 P 00. Orpiment. As' S3. ORTIIORHOMBICe SYN. —uripigment, Gelbe Arsenblende, Rauschgelb, Operment, Arsenic sulfure jaune. It crystallizes as a right rhombic prism of 100~ 40'. The crystals usually show the brachydome, the rhombic prism, macro- and brachyprisms, macro- and brachypinacoids and an octahedron. It has a crystalline structure and a very easy cleavage parallel to the macropinacoid. On the 158 LECTURES ON MINERALOGY. cleavage faces its lustre is pearly, somewhat silky, because the cleavage faces are frequently striated; elsewhere it is resinous. Translucent. Its color is a decided lemon-yellow; sometimes slightly orange colored, owing to a slight admixture of Realgar. Its streak is yellow and a little paler than the color. By cleavage, very thin lamelle can be detached, which are flexible but not elastic: IH.=1.5-2. G.=3.48. Composition, As 61, S 39. Pyr. &c. B. P. In a closed tube it fuses and volatilizes, giving a dark yellow sublimate; acts otherwise like Realgar. Dissolves in aqua regia and caustic alkalies. It has been found at Edenville, N. Y., on Arsenopyrite. FORMULJE OF THE CRYSTALS. P. XXX. Fig. 15. ooP. oP2 oo P oo. oo 2. oo P oo. P.o 2 P2. ANTI1YIONY. Antimony. Sb. HIExAGONAL. SYN.-Gediegen Antimon, Antimoine natif. It crystallizes in rhombohedra of 87~ 35', with easy cleavages parallel to the base, so that in mass it is always lamellar, and the faces of the larnellse are more or less large. Its lustre is bright and metallic when pure. The varieties containing arsenic have a very brilliant lustre on the fresh fracture, but this soon becomes gray and dark from a superficial oxidation, which is more easily effected on arsenic than antimony. Color and streak, tin-white. Very brittle. HI.=3.35. G.=6.646-6.72. Composition, when pure, Sb. It generally contains one or two per cent. of impurity. Pyr. &e. B. P. On Ch., it is fusible and gives off vapors, which condense at some distance from the assay in a white ring. It is easy to distinguish this from arsenic, which is much more volatile. The white coating in the R. F. tinges the flame'bluish-green. It is generally found'in lamellar masses, having almost a compact fracture. The varieties, which have very large lamellse, are almost pure antimony. The others usually contain arsenic, the proportion of which can be distinguished to a certain degree by the size of the lamellse. The proportion of arsenic is sometimes sufficiently large, to give the specimen the shelly character so common in Native Arsenic, the presence of which is easily verified by the blowpipe. It is sometimes found in large masses which are somewhat coated with a yellow oxide. It has been found in the U. S. at Warren, N. J. Senal'montite. 9b. ISOMETRIC. SYN.-Antimoine oxyde octae'drique. It crystallizes in regular octahedra, with a trace of octahedral cleavage. The fracture is almost lamellar, with a bright lustre which is always adamantine or resinous on the fresh fracture. It is generally semi-transparent or semi-translucent. When pure, it is colorless. Streak, white. U.=2-2.5. G.=5.22-5.3. Composition, Sb 83.56, 0 16.44. Pyr. &c. B. P. In a closed tube, fuses and partly sublimes. On.Ch.,. it becomes reduced in the R. F. and is volatilized, coloring the flame greenish-blue. It is insoluble in f. LECTURES ON MIINERALOGY. 159 It is generally found in crystallized masses, with the crystals interlaced. If the crystals are very small, it becomes granular. It is generally white or without color, but sometimes grayish, when it has become mixed with clay. With the crystallized varieties are associated others that are compact and earthy and which have almost a conchoidal fracture, in which no crystalline character can be seen. Sometimes it resembles clay. It must then be determined by its density or blowpipe reactions. This mineral has only been found in Algeria, and is very rare in collections. FORMULAIg OF THE CRYSTALS. P1. XXX. Fig. 16. 0; characteristic form. Oxide of antimony is found crystallized in two systems, the isometric and the orthorhombic. It is therefore dimorphous. To the isometric oxide the name Senarmontite has been given, and to the orthorhombic, Valentinite. A third oxide has been found, but not crystallized, so that it is possible that it may be trimorphous. Valetntinite.'ib. ORTHORHOMBIC. SYN.-Weiss-Spiessglaserz, Antimonblithe, Antimoine oxyde'. It crystallizes in a right rhombic prism of 136~ 58', with an easy cleavage parallel to the prism. It is frequently found as little crystals on the surface of Stibnite. The usual form is a combination of the prism with the brachypinacoid and domes. Its fracture is lamellar in the direction of the brachypinacoid, which has a pearly lustre. The other faces are either adamantine, or dark and striated. Color, white, peach-red, gray or brown. Streak, white. ].=2.5-3. G.=5.566. Composition, Sb 83.56, O 16.44. Pyr.&c. e. B. P. In the R. F., it is reduced and gives the white sublimate characteristic of antimony. Heated in a tube, it melts without volatilizing, which distinguishes it from tellurium. It is insoluble in R. In Algeria it has been found in large masses on the outcrop of veins of Stibnite. These masses are made up of spheres, formed by little acicular crystals, diverging from a centre and fastened together. They have a very bright lustre, which is at the same time silky and adamantine. The open spaces between the spheres are filled up by a yellow pulverulent mass, which is an intermediate oxide. The density of this mass is almost 5, which prevents it being confounded with other earthy minerals. In detached crystals it resembles Stibnite or Gypsum, but it can be distinguished by its chemical characters. The adamantine lustre and density make it resemble the compounds of lead, but there is no compound of lead, which is found in this state. The intermediate oxide which is associated with these masses, seems to be the result of decomposition of the ores of antimony by the surface waters, and is often found as crusts on their surface. FORMULA OF THE CRYSTALS. PFig. 17. XXX../g. 17. oo P oo. 00 P. lc. 2P2. 160 LECTURES ON MINERALOGY. Stibnite. Sb2 S'. ORTHORnOMBIC. SYN- Gray Anti Antimony, Antimonite, Grauspiessglaserz, Antimonglanz, Antimoine sulfur6. It crystallizes as a right rhombic prism of 90~ 54', with a cleavage parallel to the brachypinacoid so easy, that the lamelle can frequently be detached with the nail. It is found in crystals, more or less perfect, which show the two general forms, P1.XXX, Figs. 18 and 20. The second form, _Fg. 20, is less common. These crystals are generally striated and cylindrical. They are usually grouped together and divergent, or arranged in groups, which are sometimes several decimeters in length. The crystals are generally disengaged towards their extremity, so that the terminations can be seen. The fracture is generally sub-conchoidal. The cleavage faces are scratched with the nail, but the other faces are harder. The color is lead-gray, with a metallic lustre that is often very bright. It frequently becomes tarnished when exposed to the air, and is sometimes iridescent, and sometimes almost a dead black. Streak, same as color. The lamellke are flexible but not elastic, and make a dark streak on paper.!H.=2. G.=4.516-4.612. Composition, Sb 71.8, S 28.2, Pyr. &c. B..P. It is fusible without the aid of the blowpipe. In the 0. F. it becomes roasted, giving off sulphurous fumes. On Ch., in the R. F., it gives the antimony coat and colors the flame greenish-blue. The crystalline varieties are sometimes bacillary and divergent at the same time. They then show a fibrous and lamellar structure and are often iridescent, which appears to be owing to a commencement of oxidation. The crystals are generally associated with an earthy or stony gangue, or with a mass of Stibnite, which is not well crystallized. The fracture of these masses is always lamellar, but only in one direction, which distinguishes it from Galenite, which has three cleavages. With Stibnite other substances are associated which have the same general aspect, in capillary crystals grouped together and divergent, which, in some localities, become woven together like Native Antimony. They are minerals of antimony having a definite composition, generally sulphoantimoniurets of lead. Before the blowpipe, these minerals give the reactions for lead, as well as for antimony. There are also antimonio-sulphurets of iron, which are found in amorphous and granular masses. In the U. S., Stibnite occurs in Maine, New Hampshire and Maryland. Argentiferous varieties have been found in Nevada. FORMUL2E OF THE CRYSTALS. PI. XXX. Fig. 18. oo P. P. ooP oo; the mostusual form..Fig. 19. The preceding, with 2 P 2. Fig. 20. o P. ~P. oo P o. Fig. 21. ooP co-P o. P. P. 2P2.;P2. Poo. Kermesite. gb+2 Sb Sl. MONOCLINIC. SYN.-Pyrostibite, Antimonblende, Rothspiessglaserz, Antimoine oxide sulfure. It crystallizes as an inclined rhombic prism. It is usually found as capillary crystals, having a basal cleavage. Lustre, adamantine or metallic. Translucent. Color, cherry-red. Streak, brownish-red. IH.= 1-1.5. G.=4.5-4.6. Composition, Sb 75.3, S 19.8, 0 4.9. LECTURES ON MINERALOGY. 161 Pyr. &c. B. P. In a closed tube, blackens, fuses and gives a white sublimate. If heated strongly, a black or dark red.sublimate is formed, otherwise it acts like Stibnite. Its formation appears to be owing to the decomposition of Stibnite, either by the vapor of water or damp air. It occurs in fine fibres which are usually capillary and divergent, or in silky tufts. Sometimes they lie flat upon the gangue and are irregularly woven together. Its principal character is its cherry-red color, which is rather brownish and perfectly distinct from that of Erythrite. To Kermesite belongs a mineral called Silver Tinder. It has a variable composition and an argentine lustre. It is never crystallized and is quite light and occurs as a more or less earthy mass, associated with a gangue. URANIUM. Uraninite. la S. ISOMETRIC. SYN.-Pitchblende, Uranpecherz, Urane oxydule'. It has been found as an octahedron associated with a cube or rhombic dodecahedron, but usually it only shows traces of crystallization. Its fracture is unequal and sometimes conchoidal. Lustre,'submetallic, greasy or dull. Opaque. Color, intense black, grayish, greenish or brownish. Streak, a lighter brown, grayish, olive-green a little shining. 1i.=5.5. G.=6.4-8. Composition, U 32.1,: 67.9. The degree of oxidation of the uranium appears to be variable, and is not very well determined. The mineral appears to be generally a mixture of several metallic oxides. Pyr. &c. &e B. P.a It is infusible. It colors the flame green, which has a different shade from that of boracic acid or copper. With fluxes, it gives a greenish-yellow bead in the 0. F., which becomes green in the R. F. It is not acted on by the non-oxidizing acids. Aqua regia and 1t dissolve it to a yellow solution, from which ammonia precipitates the uranate of ammonia, which is flaky and yellowish. Its fracture and lustre make it resemble Triplite, but it is distinguished by its density, which is near 7, and which is its distinguishing feature. It is frequently covered with a pulverulent yellowish coating, which is uranic acid or some other intermediate oxide, or a subsulphate or phosphate of uranium. Autunite. tG2 Tf+&a fH+7 fi. ORTHORHOMBIC. SYN —Lime-Uranite, Uranit, Kalkuranit. It crystallizes as a right rhombic prism, the angle of which is very near a right angle. It has a very easy cleavage parallel to the base, which gives it a very lamellar structure, both on its natural and cleavage faces. It is usually found as a crystalline incrustation, which has a fan-shaped appearance, as they are formed of a large number of crystals placed together. It is ordinarily impossible to distinguish any form. Its lustre on the base is pearly, elsewhere almost adamantine. Translucent. It has an orange-yellow color, showing greenish reflections however, owing to traces of copper. Streak, yellowish. IH.=2-2.5. G=3-05-3.19.. Composition, U 62.7, Ca 6.1, P 15.7, 1 15.5. Pyr. &c. B3:. P. Melts in the R. F. to a black globule, first swelling and losing its water. It is soluble in 1, giving a yellow solution. In the U. S., it is found at Acworth, N. H., and at Philadelphia, Pa. 11 162 LECTURES ON MINERALOGY. Torberitite. J2 P-+du 1+-7 S. TETRAGONAL. SYN.-Copper-Uranite, Kupferuranit, Chalcolith, Uranglimmer, Urane oxide'. Its general characters are the same as those of Autunite; it has the same easy cleavage, and is usually well crystallized. The crystals are often tabular and sometimes show traces of octahedra. The crystals are sometimes made up of crystalline plates, piled the one on the other. The base has a pearly lustre and is pale green. The vertical faces are vitreous and darker in color. They form coatings on the gangue, reposing usually on,the base and are quite analagous to Mica, except in their color. Lustre, pearly on the base, elsewhere adamantine. Transparent, translucent. Color, various shades of green. Streak, paler than color. Sectile. I.=2-2.5. G.=3.4-3.6. Composition,:; 61.29, Cu 8.44, P 15.57, 11 15.05. Pyr. &c. B. P. In a closed tube, yields water. Fuses at 2.5 to a blackish mass, coloring the flame green. Gives the reactions for uranium and copper. FORMULX OF THE CRYSTALS. Pl. XXX. Fig. 22. P. OP. Fig. 23. coP. P. OP. Fig. 24. P. OP. ooP oo. Flg.25. P. OP. Pco. Fig.26. OP. ~P. 2 P. Fig. 27. oP. ooPco. 2P. ~P. O P. MOLYBDENUM. Mvolybdite.' o. ORTHORHOMBIC. SYN.-Molybdine, Molybd/noker. It crystallizes as a right rhombic prism of 136~ 48'. It is isomorphous with Valentinite. It is found in capillary crystals tufted or radiated, or as a coating on Molybdenite, resulting from its decomposition. Lustre of the crystals, silky, of the incrustation, earthy. Color, straw-yellow. H.-=l-2. G.=4.49-4.5. Composition, Mo 65.71, 0 34.29. Pyr. &e. B. P. On Ch., fuses and coats the coal with yellow crystals near the assay, which are white on the outer edge of the coating. The coating in the R. F., becomes blue, and then red after long heating. With borax in the 0. F., it gives a bead, yellow while hot, and colorless on cooling; in the R. F., the bead becomes black. It is found on New York Island, associated with Molybdenite, also in Pennsylvania and Georgia. Molybdenite. Mo S2. MONOCLINIC? HEXAGONAL? SYN.-Molybdiinglanz, Wasserblei. It is found in tabular hexagonal prisms, with a cleavage parallel to the base. It is usually found in thin scales of a grayish-blue color, which are flexible but not elastic, and which soil the fingers with a bluish-gray stain. Lustre, metallic. Opaque. Color, lead-gray. Streak, same as color. L=. 1-1.5. G.=4.44-4.8. Composition, Mo. 59, S 41. Pyr. &e. B. P. On Ch., after heating some time it burns, giving off a sulphurous odor, and leaving a yellowish infusible residue, which is molybdic acid.. Decomposed by &. It resembles Graphite somewhat, but it is blue and, acts differently. On glazed porcelain, it gives a greenish streak, while Graphite gives a black one. LECTURES ON MIN ERALOGY. 163 COPPER. Copper. Cu. ISOMETRIC. SYN.-Gediegen Kupfer, Cuivre natif. It, crystallizes generally in cubes, octahedra, rhombic dodecahedra or tetrahexahedra. It is frequently found regularly crystallized in large arborescent masses, ramified and dendritic, which are formed of cubes and octahedra more or less lengthened out and joined together. It is also found in thin sheets, which cover or penetrate different substances. Its fracture is hackly. Lustre, metallic. Color, copper-red. Streak, metallic, shining; ductile and malleable. H.=2.5. G.=8.838. Composition, copper with a little silver, bismuth, etc. Pyr. &c. B. P. Fuses easily. Soluble in acids. Its density is less than that of melted copper, which is 8.921 when simply melted, but when hammered, it. is 8.952. Its sonority is also different, which would seem to show that it has been formed in the wet way, either by chemical or galvanic precipitation. What appears to corroborate this opinion is that it is often found moulded on crystals and other substances, taking pseudomorphic forms. Thus, Calcite and other minerals which would not have resisted the high temperature of the fusion of copper are often found coated with it. It almost always contains a certain proportion of silver, which cannot always be seen, but which appears to show a simultanbous precipitation of the two metals. It is always easy to recognize it by its metallic lustre and red color, which however is sometimes masked by superficial action, but it is easily seen by breaking or scratching with a knife. It is also found in very large amorphous masses in Lake Superior. The largest ever found weighed 420 tons and contained 90% of copper. FOVRMUL.E OF THE' CRYSTALS. P1. XXXI. Fig. 1. o 02; a frequent forrm. Fig. 2. Hemitrope of the preceding; composition'face 0. Fig. 3. The same, flattened; resembles an hexagonal pyramid. Cuprite. ~-u. ISOMETRIC. SYN.-Octahedral Copper Ore,: Rothkupfererz, Ziegelerz, Cuivre oxidul6, Chalcotrichite, Kupierbliithe. Its crystals are generally the octahedron which is either simple or modified, sometimes the rhombic dodecahedron, but rarely, the cube. Sometimes the cube is lengthened to capillary forms. It has an octahedral cleavage which makes it often look lamellar on its fracture. Its fracture is conchoidal or uneven, sometimes lamellar. On the natural faces its lustre is quite bright and is semi-adamantine or semi-metallic. In some varieties it is earthy. Its crystals are sometimes transparent or translucent in thin pieces. Its color is dark blood-red; sometimes almost black. Its streak is dark cochineal-red. H1.=3.5-4. e G.=5.85-6.15. Composition, Cu 88.8, 0 11.2. Pyr. &e B. B P. In the 0. F., it is infusible and gives a black scoria. In the R. F., it gives a button of metallic copper, which is malleable and ductile.'Soluble in HC1 and f. It is often found as crystalline masses, rmade up of crystals disseminated in a gangue or interlaced among themselves. These are generally small 164 LECTURES ON MINERALOGY. and indistinct, and give to the whole mass a ramified or scoriaceous look. At Chessy, near Lyons, France, Cuprite wvas formerly found in large crystals. They are transformed on their outside into Malachite, without having the regularity- of their faces disturbed. This is sometimes superficial, and sometimes only a little core of Cuprite is left, and in others the pseudomorphism is complete. The faces of some of the crystals are simply concave, while others are completely hollow. This is generally true of the octahedron, the edges of which, however, are very prominent, the faces being very much sunken. It also occurs in semi-lamellar masses of a lighter red than the crystals, having almost a granular or compact fracture. These masses have a density above 5, and are almost always accompanied by some stain of copper. It might be mistaken for Hematite or Magnetite, but the streak and blowpipe characters are different. When found in capillary crystals, which are generally elongated cubes, it is called Chalcotrichite. This is frequently associated with Limonite. It has a peculiar lustre, and its capillary condition and reactions with the blowpipe, make it easy to distinguish. This variety is quite rare, When found in large quantities, it is a valuable ore of Copper. In the U. S. it has been found at Somerville, N. J., and Cornwall, Pa., and Lake Superior. FORMULFE OF THE CRYSTALS. Pl. XXXI. Pig. 4. 0; the most frequent form. Fig. 5: oo0; also characteristic. Fig. 6. ooO. 0. Fig. 7. Octahedron, with cavernous faces. Fig. 8. 0. 202. oo02. 30 3. 20. coO. oocoo. Chalcocite. *Cu S. ORTHORHOMBIC. SYN.-Vitreous Copper, Copper Glance, Chalcosine, Kupferglanz, Cuivre sulfur6. It crystallizes as a right' rhombic prism of 1190 35'. By fusion and decantation, it can be artificially obtained in octahedra. This dimorphism is only a question of temperature. The angle of the prism gives rise to limit forms. There is a trace of cleavage parallel to the prism. Crystals are not abundant, but they show appearances of limit prisms, which resemble hexagonal types. The base of the prism shows slight striations, which are parallel to brachypinacoid. These striations serve to distinguish the simple crystals from those which are formed by the union of six crystals placed together upon the face of the prism. The base of such crystals shows radiated striee. It has another peculiar macle, formed by four crystals joined in a cross around the faces of the brachydome. Fracture, conchoidal. Lustre, metallic. Color and streak, dark blue, almost black. It is ductile, and can be easily cut with a knife into curved shavings. IH.=2.5 to 3. G.=5.5 to 5.8. Compositions Cu 79.8, S 20.2. Pyr. &c. B. P. It melts in the flame of a candle, giving off sulphurous acid. Gives the reactions for copper. It is soluble in hot, but is not acted upon by cold. Besides the crystallized varieties it is found in semi-lamellar,'semi-compact masses, with almost a conchoidal fracture of a bluish color, which in old fractures is very dark. It occurs sometimes in schistose masses. It has also been found in ramified or stalactitic forms, which appear to be pseudomorphs after Native Copper. It is usually ductile, but has been found in masses which do not possess this property, although having the LECTURES- ON MINERALOGY. 165 same physical appearance. It is then probably alloyed with a considerable proportion of Argentite. It resembles Argentite, but the latter is more sectile, has a different lustre and gives different reactions with the blowpipe. The mines at Bristol, Conn., furnished some of the most beautiful specimens, that have ever been found. It has been found in New York, New Jersey, Virginia and other states. FORMULA OF THE CRYSTALS. Pl. XXXI. Fig. 9. OP. ooP. ocoo. -Fig. 10. OP. 3P. ePoo. fig. 11. OP. CoP. oo P o. J P. P-i co. Fig. 12. Group of twin crystals; the lower half with the composition-face co P, the upper half twinned with a face of -4P oo. Fig. 13. Cruciform twin, having OP and Co P of one crystal parallel respectively to co 1P oo and 0 P of the other. Bornite. (eu, Fe) S. ISOMETRIC;. SYN.-Erubescite, Purple Copper Ore, Peacock Ore, Buntkupferkies, Cuivre pyriteux hepatique, Philipsite. It is found in cubes, octahedra and' rhombic dodecahedra, which are either simple or macled on one of the faces of the octahedron, but crystals are very rare. It has traces of an octahedral cleavage. Its fracture is generally unequal and conchoidal. Lustre, metallic. Its color is reddish-brown or a dark violet-blue, with a great variation in colors, owing to tarnish. Streak, blackish bronze-yellow. H1.=3. G.=4.4-5.5. Composition, fobr ( — 4u+1 Fe) S, is Cu 70.13, Fe 7.76, S 22.11. Pyr. &e. B. P. In a closed tube, gives a faint sublimate of sulphur. In the O. F. it is roasted with a sulphurous odor and gives in the R. F. a half-melted globule, which is attracted by the magnet. Soluble in It is generally found compact and shows such a brilliant play of colors, that it is not possible to confound it with anything else. It is fbund at Bristol, Conn., in crystals. It occurs massive in Mass., New Jersey, Penn. and elsewhere. FORMULAE OF THE CRYSTALS, Pt. XXXI. Fig. 14. cOF o. 0..Fig. 15. c00. 202. Chaleopyrite. u3a S+Fe S+Fe S'.'TETRAGONAL. SYN.-Copper Pyrites, Kupferkies, Pyrite cuivreuse, Cuivre pyriteux. The prism is very near the cube. It is found in crystals or in concretionary or amorphous masses. The crystals are sometimes octahedra but more frequently sphenoids, which, on account of the small difference in the edges, resemble regular tetrahedra. But of the three edges which join at the same solid angle, two only are of the same kind, so that the modifications that can be produced upon them are not in pairs of 3, but of 2 and 1 which shows it to be tetragonal. It has traces of cleavage parallel to the vertical faces of the prism. Fracture, conchoidal or uneven. It has a metallic lustre and a brass-yellow color, which is deeper than that of Pyrite. It is subject to tarnish and is often iridescent. H..=3.5-4. G.=4.1-4.3. Composition, Cu 34.6, Fe 30.5, S 34.9. Pyr. &e. B. P. In a closed tube, decrepitates ~and gives off S. 166 LECTURES ON MINERALOGY. On Oh., melts, giving off sulphurous acid, and yields a magnetic, globule. Soluble in R~. It often shows on amorphous masses a play of colors, which is owing to a superficial alteration. This iridescence is sometimes found on the fracture when the fissures have been acted on by the same agency that affected the surface. These colors are very bright, but are' generally lighter than those of Bornite. The concretionary varieties are generally little mamelonsseparated from each other, which are quite smooth on their surface and stalactitic in character. The amorphous masses, which are the most common, are recognized by the yellow color, which is often variegated, the unequal fracture and hardness. It does not strike fire with the steel, which character distinguishes it from Pyrite, with which it is often associated. It is a valuable ore of Copper and is found in many localities in the U. S. FORMULAE OF THE CRYSTALS. Pl. XXXI. Fig. 16. P; the two sphenoids equally developed. Fig. 17. P 2 -. Fig. 18. P. OP. 2 P o. P oo. Fig. 19. The same, but with P P one sphenoid further developed than the other. Fig. 20.'. 2 2 P P ooPoco. Fig. 21. CoP. 2 Poo. -lig. 22. Hemitrope; 2 2 composition-face P. Fig. 23. Hemitrope of Fig. 18. Fig. 24. Twin crystal; composition-face P co. Fig. 25. Twin crystal of the form Fig. 17. PI. XXXII. Fig. 1. Twin crystal, composition repeated four times. Fig. 2. Twin crystal; Cornwall. Fig. 3. Twin crystal; 0 P. P. P. 3 P. 3 P oo; composition-face P mo. Tennantite. 4 (C3u,Fe) S+As2 S3. ISOMETRIC. SYN.-Arsenikalfahlerz, Kupferblende, Zincfalllerz. Its dominant form is the rhombic dodecahedron, with small faces of the tetrahedron,PI. XXXII. Fia. 8. It has traces of dodecahedral cleavage. Fracture, uneven. Lustre, metallic. Color, blackish lead-gray to ironblack, and in old fractures, dull black. Streak, dark reddish-gray. 1.=3.5 to 4. G.=4.37 to 4.53. Composition, Cu 47.70, Fe 9.75, As 1.2.46, S 30.25. Pyr. &e. B. P. In a closed tube, gives a sublimate of sulphide of arsenic. In an open tube, sulphurous fumes and arsenous acid. On Ch., filses with intumnescence to a magnetic globule. In the R. F. gives a brittle globule of copper. There are two compounds of copper, having very nearly the same composition, in one of which arsenic predominates, and in the other antimony. The former is called Tennantite, and the latter Tetrahedrite. These two varieties show different crystalline types, although they both crystallize in the isometric system and both show the hemihledry with inclined faces. LECTURES ON MINERALOGY. 167 Tetrahedrite. 4 (6u, Fe, Zn, Hg,- Ag) S (Sb, As)2 53. ISOMETRIO. SYN.-Gray Copper Ore, Fahlerz, Cuivre gris, It crystallizes in tetrahedra, which are usually modified by the hemitetragonal trisoctahedron. They are rarely simple, and show traces of a tetrahedral cleavage. Fracture, subconchoidal or uneven. Its lustre is bright and metallic, both on its fracture and on the natural faces of the crystal, and does not become black on exposure, and is never resinous like that of Bournonite. Its color is a blackish-gray, which is more or less dark. Its streak is gray, and much lighter than that of Tennantite. 1[.=3-4f.5. G.=4.5-5.11. Composition, Cu 19-25, Fe 2-7, Zn 1-7, Ag 0-31, As 0-11, Sb 11-28, S 19-26. Pyr. &e. B. P. In the 0. F., it is roasted, giving a slight odor of arsenic, and fumes of antimony, and in the R. F., gives a brittle globule of copper. Decomposed by R. It is found in masses with or without gangue. They are easily distinguished by their color and lustre, and their granular appearance. They often have blue or green stains like other minerals of copper. It sometimes resembles compact Galenite, but its color is a much lighter gray, and it has no tinge of blue. It resembles Chalcocite, but this is sectile and less bright, and it does not have the same density. Bournonite has a conchoidal fracture, a resinous lustre, and is not so hard. It is distinguished by the color of its streak, from Hematite, Magnetite and the oxides of Manganese. The blowpipe distinguishes it from other minerals. It is worked for copper and often for silver. It has been found in Arkansas, California, Arizona and Nevada. FORMULAE OF THE CRYSTALS. Pt. XXXII. 0 0 0 0 Fig. 4. ig.'. Fi. Fig. 6. -2-. oO oo. -/g. 7. O 202 O 2. - 2 2 Fig. 8. co 0. oo 0 o.; with the rhombic dodec202 ahedron predominating. F-g. 9. 2 o 0. Fig. 10. The preceding, with 0. Fig.'11. The form Fig. 7, with. and co 0. Fig. 12. 202 2 02 2' o:0 oO. - 2 oo03. Fig. 13. The preceding, with 2 0. Fig. 14.. Interpenetrating tetrahedra; composition-face 0. Fig. 15. Interpenetrating tetrahedra. Fig. 16. Twin crystal, formed by repeated twinning similar to the preceding figure. Chalcanthite. Mu +-5 IA. TRICLINIC. SYm.-Cyanosite, Blue Vitriol, Kupfervitriol, Cuivre sulfate'. It is rarely found crystallized, but is generally amorphous, sometimes concretionary and mamelonated on the surface of gangues. Lustre, vitreous, Transparent, translucent.. Color, different shades of blue. Streak, colorless. Brittle. Taste, metallic and astringent. HI.=2.5.- G.=2.13. Composition, Ou 31.8, g 32.1, I 36.1. 168 LECTURES ON M:INERALOGY, Pyr. &e. B. P. In a closed tube, yields water and then 8. On Ch., in the R. P., gives metallic copper. Soluble in water. It is frequently found in abandoned mines of copper as an accidental product resulting from the decomposition of Chalcopyrite, produced by hot damp air. It has all the characters of the sulphate of copper of the laboratories. It has been found in the copper mines of Tennessee and Georgia. FORMULAE OF THE CRYSTALS. Pl. XXXII. Fig. 17. P'. ooP'. 0' P. co P C. o co. oo' P2. 2'I2. Brochantite. 2 CUa -+dU S-+4 H. ORTHORHOMBIC. SYN. —Krisuvigit, Warringtonite. It crystallizes as a right rhombic prism of 104~ 30'. It is generally found in groups of acicular crystals. It has an easy cleavage parallel to the brachypinacoid. Lustre, vitreous, pearly on the cleavage faces. Transparent, translucent. Color, emerald-green. Streak, paler than color. Hfl.=3.5-4. G.=3.78-3.87. Composition, Ou 69, S 19.9, t 11.1. Pyr. &ec B.. P. In a closed tube yields water, and afterwards B. On Ch., in the R. F., gives metallic copper. It resembles Malachite in its exterior characters. It is found in little crystals which can rarely be measured, as they are very generally capillary. It is also found in little mamelonated and fibrous masses. It is distinguished from Malachite, by not effervescing. They are both soluble in ammonia, but Brochantite gives a precipitate with chloride of barium. It resembles Atacamite, but has a lighter color. The blue color so easily shown before the blowpipe with Atacamite, is less easily produced with Brochantite. It has been found in Cornwall, Pa. FORMULA: OF THE CRYSTALS. Pi. XXXII. Fig. 18. ooPoo. coP. Poo. Pco. Atacamite. Cu C1 ft+3 Cu Bf. ORTHORHOMBIC. SYN.-Salzkupfererz, Cuivre chlorure. It crystallizes as a right rhombic prism of 112~ 20'. Cleavage perfect, parallel to the brachypinacoid, imperfect, parallel to the macropinacoid. The crystals are quite small. The fracture may be unequal, conchoidal or fibrous. Lustre, adamantine and vitreous. Color, dark emerald-green. It is much nearer olive-green than Malachite. Streak, apple-green. H.=3-3.5. G.=4-4.3. Composition, Ou 53.6, CuCl 30.2, f 16.2. Pyr. &c. B. P. In a closed tube gives off water. On Ch., fuses and gives an intensely blue color to the flame, before it is reduced. All the salts of copper when heated with IIC1 show this character, but as the chloride is much more volatile than the others, it shows it in a higher degree. It is soluble in acids, without effervescence and without residue. Ammonia dissolves it, and colors the solution blue. It is found sometimes in little crystals, sometimes in little fibrous tufts covering a gangue, which is generally one of the oxides of iron. This coating is made up of crystals joined together, showing bands of different shades of green like Malachite. These fibers are closer together than in LECTURES ON MINERALOGY. 169 Malachite, so that the lustre is not silky. It is also found as very small crystals, lining cavities in certain lavas. It is also found as sand, which can be distinguished by its color. It results from the action of water on large masses. It is found in this state, at Atacama, in Chili. When it is found abundantly, as in Chili, it is a valuable ore of copper. FORMULE OF THE CRYSTALS. PI. XXXII. Fig. 19. ac. Ioo. ooP oo, Libetlienite. Cu4 -+t[. ORTIORHOMBIO. SYN.-Apherese.'it crystallizes as a right rhombic prinm of 92~ 20'. Its usual forms are a combination of the prism, rhombic octahedron and brachydome, giving the crystalsi a roof-shaped appearance; the faces are very often curved. It has a very indistinct cleavage parallel to the macro- and brachypinacoids. Fracture, conchoidal or uneven. Lustre, resinous. Translucent, opaque. Color and streak, dark olive-green. I[.=4. G.=3.6-3.8. Composition, Cu 66.5, P 29.7, ft 3.8. Pyr. &c. B. P. In a closed tube, yields water and, blackens. Fuses and colors the flame green. On COh., gives metallic copper. Soluble in R. It is often found globular, or mamelonated, associated with Quartz and Chalcopyrlte. FORMULAE OF THE CRYSTALS. Pi. XXXII. i.2o0. 0 cP. P O. P. Dlivenite. OU4 ( XS, ) + -f. -ORTHORHOMBIC. SYN. —Olive Copper Ore, Olivenerz. It crystallizes as a right rhombic prism of 92~ 30'. Its crystals usually show a combination of the prism and the macro- and brachypinacoids and domes. It has an easy cleavage parallel.to the prism. Its fracture is conchoidal or uneven. Translucent, opaque. Color, different shades of green, brown, yellow or grayish-white. Streak, olive-green or brown. Brittle. H.=3. G. = 4.1-4.4. Composition, Ou 57.4, Xs 35.7, P 3.7, fi 3.2. Pyr. &c. B. P. In a closed tube, gives off water. Fuses at 2, coloring the flame bluish-green and giving a crystalline mass on cooling. On Ch., deflagrates and gives arsenical fumes. With soda in the R. F., gives a button of copper. Soluble in Si. It is oftea found in fibers of a very light green color, which are often very much bent; it is sometimes found lamellar or granular and rarely quite earthy, of a grayish color. It is usually found coating, or associated with Quartz. Some varieties resemble Libethenite, but they can generally be distinguished by the greater quantity of arsenic present and, when crystallized, by the general absence of octahedra. Some of the fibrous varieties resemble Atacamite, but are distinguished by the blowpipe. Pl. XXXII. FORMULAS OF THE CRYSTALS. Fig. 21. ooP. oo P oo. ccP. Poo. Poo. Liroconite. ou3 (Xs, i) +(r 0uS+~3 M1) 1ft+9 ft. MONOCLNIC. SYN-Linsenerz, Chalcophacit. It crystallizes as an inclined rhombic prism of 74~ 21'. It generally 170 LECTURES ON MINERALOGY. shows the prism and clinodome, giving the crystals a roof-shaped appearance. The crystals are generally quite small. Its fracture is conchoidal or uneven. Lustre, vitreous. Translucent. Color and streak, blue or green. N1[.=2 —2.5. G;=2.882-2.985. Composition, Cu 36.38, is 23.05, 9 3.73. Al 10.85, ft 25.01. Pyr. &c. B. P. In a closed tube gives off water, and turns olivegreen. Cracks, but does not decrepitate, and fuses to a dark gray slag. On Ch., cracks, deflagrates and gives the reaction for arsenic and copper. Soluble in iR. It is usually associated with other ores of Copper. The blue varieties resemble Chalcanthite, but can be distinguished by their insolubility. FORMUL2A OF THE CRYSTALS. Pl. XXXII. Fig. 220 ~oP. P co. Miialachite. OU2 d+It. MONOCLINIc. SY. — Green Carbonate of Copper, Cuivre carbonate vert. It crystallizes as an inclined rhombic prism of 104~ 28'. Crystals are generally very small and rare. They are not often sufficiently distinct to admit of being measured. It has as easy basal cleavage. It is found crystallized in silky tufts, made up of crystals which are more or less distinct; these crystals are sometimes translucent, and are always intensely green. These silky tufts are often scattered over a gangue. It is often found as large crystals, which are pseudomorphs after Cuprite or Azurite. Its fracture is unequal, conchoidal, or fibrous in the concretionary varieties. Lustre of the crystals adamantine, of the fibrous varieties, silky; sometimes dull or earthy. Translucent, opaque. Its color is green, and may be of different degrees of intensity. Streak, paler than color. H.=3.5-4. G.=3.7-4.01. Composition, Onl 71.9, 0 19.9, f 8.2. Pyir. &e. B. P. In a closed tube blackens and gives off water. It melts at 2, coloring the flame green, and gives a scoriaceous mass. In the R. F., a globule of metallic copper is easily produced. Soluble in acid with effervescence. It is usually found in concretionary masses, which have a fibrous fracture, rarely conchoidal. Their lustre is silky and velvety. These masses present a variety of shades, which are owing to different causes, a change in the direction of the fibers, a difference in the state of hydration of the mineral, or an admixture of other substances. This banded, silky and velvety appearance, causes Malachite to be much sought for, as an object of ornament. It is often found mixed with other minerals, which cause. a change in the tint orf the green. Some varieties resemble Chrysocolla, but are distinguished by effervescing with acids. It is a valuable ore of copper, when found in large quantities. It is much used for articles of ornament, and is often employed for veneering large articles, such as tables, doors, &c. A mass weighing 40 tons, was found in Siberia. It has been found in small quantities, in most of the copper mines of the U. S. In Cornwall, Pa., it is sometimes found in quite thick pieces of a light green color. FORMULAE OF THE CRYSTALS. PI. XXXII, Fig. 23. co P. co P co. OP; twin crystal, composition-face cc P o. LECTURES ON MINERALOGY. 171 Azurite. 2 Ou C0+Cu I. MONOCLINIc. SYN.-Blue Malachite, Chessy Copper, IKupferlasur, Cuivre carbonate bleu. It crystallizes as an inclined rhombic prism of 99~ 32'. It has traces of cleavage parallel to the clinodome. The primitive form of' the crystal is very rare, but complex crystals are often found. Detached crystals are not common; they are usually scattered over a gangue or lining cavities. Its fracture is conchoidal. Lustre, vitreous, nearly adamantine. It is transparent, translucent or opaque. Its color is azure-blue; which is more or less dark. Streak, lighter than color. Brittle. ].=3.5-4.25. G.= 3.5-3.831. -Composition, Cu 69.2, 0 25.6, ft 5.2. Pyr. &c B. BP. Like Malachite. In acids it is soluble with effervescence, which is not immediate but requires heat. It is sometimes found as concretionary masses in mamelons, which are sometimes so close together as to become joined. The little crystals which protrude from the surface, then give it a velvety lustre. It has been found in little balls which are evidently the product of decomposition, since they contain some oxide in their interior. Themassive pieces do not always have a uniform color, but are found as concentric zones, made up of different shades of blue. They are also very frequently associated with other substances such as sandstone, &c. It is also found earthy, when it has no other character than its blue color, which is lighter than ordinary, as it is frequently mixed with clay, marl and sand. The crystalline varieties have a color, which prevents their being mistaken for anything else. The earthy varieties often resemble Lapis-Lazuli or Vivianite. Before the blowpipe it can be immediately distinguished fiom the former. The lustre of the earthy varieties of Vivianite is quite different, but it can easily be distinguished by the blowpipe or by acids. It has been reproduced artificially, with the same crystalline types, by submitting Cu Cl, and an alkaline carbonate to a high temperature, in a closed vessel for a long time. When found abundantly it is a valuable ore: of copper. It has been found in many of the copper mines of the U. S. FORMULAE OF THE CRYSTALS. Pi. XXXII. Fig. 24. ooP. OP. -P. i' co. Fig. 25. OP. cooP. coPco. -Pa. 3 PI. P o. Pi. XXXIII. Fig 1. OP. coPoo. ooP.~ P co; tabular crystal. Fig. 2. OP. J P o. cP.'-P. ~P oo. MERCURY. MIercury. IIg. ISOMETRIC. SYN.-Quicksiiver, Gediegen Quecksilber, Mercure natif. When solidified it crystallizes in octahedra. Lustre, metallic. Opaque. Color, tin-white. G.=13.568. Composition, pure mercury, sometimes with a little silver. Pyr. &c. B. P. On Ch., completely volatilized. Soluble in R. Mercury is found in some rocks, haying all the properties of the ordinary metal. It is usually found in globules in cavities associated with Cinnabar. These globules are sometimes strung together and are not very fluid, as the mercury is not pure, but frequently contains silver. It sometimes oceurs not associated with Cinnabar. In California, geodes or Quartz containing several pounds have been found. It is a very rare 172 LECTURES ON MINERALOGY. mineral, and has been found in states of different geological ages. It is also found in pockets. Cinnabar. Hg S. HEXAGONAL. SYN.-Cinnabarite, Zinnober, Cinabre, Mercure sulfure'. It crystallizes in a rhombohedron of 92~ 36', with cleavages parallel to the hexagonal prism. It is frequently found in crystals lining the sides of cracks. Besides the rhombohedron R, it frequently has a large number of faces belonging to other rhombohedra on the edges of the hexagonal prism. The flat crystals are usually transparent. It is also found in lamellar and fibrous masses. Generally it is in large granular masses, sometimes fibrous or compact. Its fracture is conchoidal or uneven, both in the crystals and crystalline masses. Lustre, adamantine on the faces of crystals, dull on the compact varieties. The crystals are transparent, translucent, or opaque. The color is cochineal-red, inclining to violet. Streak, characteristic vermilion-red. When it is impure the color is often black, but the streak is always red. It absorbs light easily, which often makes it opaque. It is the most refringent of all known bodies. 11I.=2-2.5. G.=8.998. Composition, Hg 86.2, S 13.8. Pyr. &c. B. P. On Ch., it volatilizes without residue. In a tube, gives a red sublimate. It is not attacked by acids and is the only sulphide which is not acted on by aqua regia. When it is pure it is easily recognized by its color and its high density, It is often impure, being scattered through bituminous limestones, when it is very black. It might be mistaken for Proustite, Rutile, Realgar or Crocoite, but it can always be recognized by its density and streak. It is very rare that the black varieties do not show some filaments, which have the natural color of the mineral. Cinnabar is the ore of mercury, from which most of that used in commerce is obtained. It is sometimes ground and used as a pigment, called vermilion. The principal supply in the U. S. comes from California. FORMUL2E OF THE CRYSTALS. PI. XXXIII. Fig. 3. R. OR. oo R. Fig. 4. o R. -2 R. -4 R. -2 R. -*R. R. {R. 2 P2. OR..Fig. 5. R. OR. o R. R. Calomel. Hg2 C1. TETRAGONAL. SYN.-Horn Mercury, Quecksilberhornerz, Chlormercur, Mercure chlorur6. The usual form is the prism of the second order, with the octahedron of the first order. Fracture, conchoidal. Lustre, adamantine. Translucent. Cleavage, parallel to the prism of the second order. Color, white, gray or brown. Streak, yellowish-white. It has the consistency of horn and is easily cut into thin, transparent shavings. I. =1-2. G.=6.482. Composition, Hg 84.9, C1 15.1. Pyr. &e. B. P. In a closed tube volatilizes without fusion. On Ch., volatile without residue. Soluble in aqua regia; decomposed by alkalies. The imineralogical assay of all the minerals of Hg, is very simple. By heating them in a tube with a little soda. almost to fusion of the glass, globules of metallic mercury condense. It is sometimes found iii the cavities of Cinnabar, or on the rocks which contain it. LECTURES ON 3MINERALOGY. 173 FORMULAE OF THE CRYSTALS. Pi. XXXIII. Fig. 6 cPc. P o. P. SILVER. Silver. Ag. ISOMETRIC. SYN. —Gediegen Silber, Argent natift It is usually found in cubes and octahedra, alone or together, or sometimes associated with the rhombic dodecahedron, and very often in tetrahexahedra. Twins are quite common. The crystals are usually distorted. Arborescent forms are also found, which are made up of distorted octahedra, branching from a given direction. Lustre, metallic. Color and streak, silver-white, but liable to tarnish. Ductile, sectile. H.=2.5-3. G.- 10.1-11.1. Composition when pure, silver, but it is usually associated with gold or other metals. Pyr. &c. B... P. Native Silver has all the characteristics of Ag. On Ch., fuses easily to a metallic globule. In the 0. F., gives a brown coating. Soluble in; the addition of a drop of ECI, shows a precipitate of chloride of silver. The density of Native Silver is not generally equal to that of melted silver, but is somewhat less and sometimes it has no more ring than pasteboard. These same characters are shown by silver precipitated by the galvanic battery, which has given rise to the opinion that this may have been the way in which it was formed. It is often found in filaments which are more or less white, and bent in every direction. These filaments, as well as the crystals, are ordinarily in a gangue of Calcite. Those which are seen disengaged in collections, have been separated by acids. The silver which is used in the arts is never pure. For coins in this country, it is alloyed with 10 % of Cu. Pure silver in the arts, is said to be 12 pennyweights fine. It is said to be 11. 10, 8 or 9 pennyweights fine, according to the quantity of alloy it contains. A mass of Native Silver from one of the Mexican mines, weighed 400 lbs., and at Freiberg, a mass weighing 1400 lbs. was found. It is found associated with a large number of minerals. In Lake Superior it occurs with Native Copper. It occurs in Idaho in large masses, associated with Cerargyrite. It is usually the result of the decomposition of other silver ores. FORMULAE OF THE CRYSTALS. Pl. XXXIII. Fig. 7. o 0 oo. Fig. 8. 303. Fig. 9. Hemitrope, compositionface O. Fig. 10. Hemitrope of the cube. Fig. 11. The same, but upon the other face of the octahedron. Fig. 12. The hemitrope, Fig. 10, flattened in the direction of the diagonal. Amalgam. Ag Hg2. ISOMETRIC. SYN.-Silberamalgam, Amalgam natif. It is always crystallized as a rhombic dodecahedron, very highly modified, but the faces are rarely distinct, as a separation of silver and mercury takes place after a certain time, so that the crystals become distorted and the edges rounded; sometimes it spreads out, and is imbibed by the rock., It shows traces of cleavage, parallel to the faces of the rhombic dodecahedron. Its fracture is conchoidal. Lustre, metallic. Opaque. Color and 174 LECTURES OS- MINERALOGY. streak, silver-white. Brittle; makes a creaking noise when cut with a knife. H.=3-3.5. G.=10.5-14. Composition, Ag 34.8, Hg 65.2. There is no invariable formula for this mineral, but the Ag and Hg oscillate around the one given. These two metals become alloyed in different proportions, without losing the property of crystallizing. Pyr. &e. B.. P. On Ch., the Hg is driven off, and a globule of Ag remains. In a closed tube the Hg sublimes and leaves the Ag. A strip of copper is whitened and an amalgam of Cu and Hg is formed. Soluble in So. It is found associated with Cerargyrite and Calomel. It resembles Native Silver, and is almost always crystallized. It does not lose its color or become black as easily as the former. Still the blowpipe must be used to discover the presence of mercury, before it call be distinguished with certainty. FORMULXE OF THE CRYSTALS. P 1. XXXIII. Fig. 13. oo O; characteristic form. Fig. 14. co O. O. Fig 15. oo0 oo. oO. Fig. 16. 202. ooO..Fig. 17. oO. Coo0o. 202. co03. 30oL. 0. Argentite. Ag S. ISOMETRIC. SYN.-Vitreous Silver, Silver Glance, Glaserz, Silberglanz, Argent sulfur'. It is often found in cubes, octahedra, tetragonal trisoctahedra and hexoctahedra alone, but usually combined one with the other. The crystals are sometimes very distinct and are often grouped. It is also found in wiry filaments. It has indications of a dodecahedral cleavage, which are not very distinct. Fracture, conchoidal or uneven. Lustre, metallic. Opaque. Color, deep iron-black with very little lustre On the natural faces. The lustre is however bright on the fracture. Streak, same as color and shining. It is ductile, receives and retains themark of the hammer. It is flexible, but not elastic. When it is pure it can be cut with a knife, giving curved shavings. I.=2-2.5. G.='7.196-7.365. Composition, Ag 87.1, S 12.9. Pyr. S&c. B. P. Melts in a flame without the aid of a blowpipe. In the 0. F., it is roasted. In the R. F., gives a metallic globule. Soluble in R9. It is also found as amorphous masses disseminated in gangues, which are usually limestone; these masses have a variable, conchoidal fracture which is rarely lamellar. It often shows in the fracture that it is both ductile and tenacious. Its softness and the look of the fracture make it resemble Bournonite, but this is more brittle, while Argentite can be cut with a knife. The blowpipe gives with this a globule of silver, with that a globule of copper and lead fumes. The specific gravity is much higher than any of the copper ores which it resembles. Its a very valuable ore of silver. It is mined as an ore in Nevada. FORMULtE OF THE CRYSTALS. Pl. XXXIII. Fig. 18. co O oo. 0; a very frequent form. Fig. 13. co 0. Fig. 19. ooOco. 202. Fig. 20. 202. Fig. 21. 202. 0oOo. 0 Fig. 22. 2 0 2; lengthened vertically. LECTURES ON MINERALOGY. 175 Proustite. 3 Ag S+As2 S3. HEXAGONAL. S.. —Ruby Silver Ore, Arsensilberblende, Argent rouge arsenicale. It crystallizes as a rhombohedron of 107~ 48'; its usual forms are the hexagonal prism and rhombohedron, the scalenhedron or hexagonal prism, and hexagonal pyramid. The forms are almost as numerous as those of Calcite. The number of faces is so large, that the crystals usually have a rounded appearance. Fracture, conchoidal or uneven. Lustre, adamantine. Transparent, translucent; highly refiingent. Color and streak, cochinealred. f1.=2-2.5.;G.=5.422-5.56. Composition, Ag 65.4, S 19.4, As 15.2. Pyr. &c. B. BP. In a closed tube decrepitates and fuses easily, giving a slight sublimate of sulphide of arsenic. In an open tube, gives sulphurous fumes and is. On Ch., gives the smell of sulphur and arsenic. After long treatment in the 0. F., it gives in the R. F. a globule of silver. Soluble with difficulty in the oxidizing acids. It is sometimes found in capillary masses, and often amorphous or crystalline, associated with other ores of silver. There are two extreme types of Red Silver, having the same general formulae, and the same crystalline form, except that in one the arsenic is replaced by antimony. There is every possible gradation between the two limits. The arsenical variety, or Proustite, is called Light Red Silver, and the antimonial, or Pyrargyrite, Dark Red Silver. It has been found in the U. S. in Nevada, Idaho and N. C. Pyrargyrite. 3 Ag S+Sb2 SS. HEXAGONAL. SyN.-Ruby Silver Ore, Antimonsilberblende, Argent rouge antimoniale. Argent antimoiie6 sulfure. Its primitive form is a rhombohedron of 108' 42'. It very frequently occurs as hexagonal prisms so highly modified as to appear rounded. Simfle crystals are quite rare. It has an indistinct cleavage parallel to the rhombohedron. Fracture, conchoidal. Lustre, metallic, adamantine. Translucent. Color, black, or very dark red. Streak, cochineal-red. H.=2-2.5. G.=5.7-5.9. Composition, Ag 59.8, Sb 22.5, S 17.7. Pyr. &e. B. P. In a closed tube, gives a red sublimate of sulphide of antimony. In an open tube, sulphurous fumes and a white sublimate of antimony. On Ch., fuses and coats the coal. Heated for some time in the 0. F., in the R. F., a globule of silver is obtained. Decomposed by f. It is sometimes found in capillary crystals or as amorphous masses associated with other ores of silver. It resembles Proustitc. The color of the two minerals is red, which is more or less bright. In Pyrargyrite it is so intense, that the mineral appears black and opaque. But there are almost always some thin points, where the color can be seen. Proustite is much lighter and is often transparent. When compact or capillary-, it can easily be distinguished from Cinnabar, Cuprite and Hematite, by the streak and blowpipe reactions. It is a valuable ore of silver and has been found in considerable quantities in Nevada and Idaho. 176 LECTURES ON MINERALOGY. FORMUL2E OF THE CRYSTALS, PZ. XXXIII. Fig. 23. ooP2. R. Fig. 24. coP 2. -4 R. 2 ~ ig. 25. R3. PI.XXXIV. Fig. 1. coP2. 2 -4'. -2R. 1R3. IR3. jR3. -Rt3. Fig. 2. ooP2. R 3. ~R3. hemitrope, composition-face O R. Fig. 3. -R. oo P2; twin consisting of four individuals, composition-face -1 R. Stephanite. 5 Ag S+ Sb2 3. ORTHORHOMBIC. SYN.-Brittle Silver Ore, Spr6dglaserz, Melanglanz, Argent sulfure fragile. It crystallizes as a right rhombic prism of 115~ 39'. Its forms are usually the prism and brachypinacoid. The prisms are always striated. It has an indistinct cleavage, parallel to the brachyprisTn and pinacoid. Fracture, conchqidal or uneven. It has a bright, metallic lustre. Translucent on the edges. Color and streak, black. H.=2-2.5. G.=6.269. Composition, Ag 68.5, S 16.2, Sb 15.3. Pyr. &c. B. P. In a closed tube, decrepitates and fuses; in an open tube gives fumes of sulphur and antimony. On Ch., decrepitates and fuses, giving the rose-colored coating of silver and antimony. After long treatment in the 0. F., in the R. F. a globule of silver is obtained. By its form, color, streak and lustre, it can easily be recognized. It is a valuable ore of silver and is mined in Nevada. FORMULIA OF THE CRYSTALS. P1. XXXIV. Fig 4. OP. P. 2 P oo; resembles a truncated hexagonal pyramid Fig. 5. OP. ooP. ooPco. Fig. 6. o 0P. co Poo. P. 2Pco. OP. _ P..Fig. 7. The preceding, with oo P oo and 2 P. Polybasite. 9 (Ag, Gu) St(Sb, As)2 S'. ORTHORHOMBIC. SYN. —Eugenglanz. It crystallizes as a right rhombic prism, the angle of which is very near 120~. The crystals are usually hexagonal in shape, and are frequently quite flat, showing but little of the prism. Fracture, uneven. Lustre, metallic. Translucent in thin splinters. Opaque. Color, black, but in thin splinters by transmitted light, cherry-red. Streak, black. H.=-2-3. G.=6.214. Composition, Ag 64.7, Cu 9.8, S 14.8, Sb 9.7. Pyr. &e. B. P. In an open tube, fuses and gives the sublimates of sulphur and antimony. On Ch., fuses, gives reactions for sulphur and antimony. With fluxes, gives reaction for copper. Decomposed by f. Quite a number of minerals are frequently described under this name; they are all quite analogous to Red Silver in their external characters. They are more opaque however, and their streak also has a brown color It has been found in Nevada. LECTURES ON MINERALOGY. 177 Cerargyrite. Ag C1. ISOMETRIC. SYN. —HIorn Silver, Silberhornerz, i-ornsilber, Chlorsilber, Argent Cdorne, Argent chlorure. It crystallizes in cubes, octahedra, rhombic dodecahedra, or combinations of two or more of them. Crystals are quite rare. The largest known came from the Poorman's lode, Idaho. Fracture, conchoidal. Lustre, resinous. Transparent, translucent. Opaque. Color, white, gray, grayish-green, or colorless when perfectly pure. Streak, colorless and shining. - Sectile, having about the consistency of horn; when cut with a knife it gives curved shavings. HE.=1-1.5. G.=5.31-5.43. Composition, Ag 75.3, Cl 24.7. Pyr. &e. B. P. In a closed tube fuses without decomposition. Fuses in a flame of a candle. On Ch., gives a globule of silver. Insoluble in S, but soluble in Ammonia. It is usually found as a coating, which is sometimes wax-like and sometimes fibrous. It is subject to alteration when exposed to the light; it then loses its color and becomes brown. It is mined as an ore of silver in South America. Extensive deposits have been found in Arizona and Nevada. FORMULAE OF THE CRYSTALS. P1. XXXIV. Fig. 8. oo oo. Fig. 9. 0. Fig. 1 o. co. Fig. 11. oO O o. 0. Bromyrite. Ag Br. ISOMETRIC. SYN. —Bromic Silver, Bromsilber, Bromit, Bromargyrite, Bromure d'argen.t. It crystallizes in cubes, octahedra, or a -combination of the cube and rhombic dodecahedron. Crystals are quite rare. Lustre, splendent. Color, when pure, yellowish-green, often a: darker green when altered. l.-=2-3. G.=5.8-6. Composition, Ag 57.4, Br 42.6. -Pyr. &c. B. P. In a closed tube acts like Cerargyrite. On, Ch., gives vapors of bromine. Insoluble in S, soluble with difficulty in ammonia. It is usually found as small concretions or coatings. It occurs in S. America, associated with other ores of Silver, but it is a veryrare mineraL FORMULXE OF THE CRYSTALS. Pi. XXXIV. ig. 8. oo oo. Fig. 9. 0. Fig. 12. 0oO., O co.: Embolite. Ag (Cl, Br). ISOMETRIC. SYN.-Chlorobromide of silver, Chlorbromsilber,- Megabromit, Micro-.bromiit, Chlorobromure d&argent. It is found in combinations of the cube and octahedron, but crystals are quite rare. Lustre, resinous. Translucent, opaque. Color, various shades of green, usually with a yellow tint, which becomes darker on exposure. Ht.=-1.5.. G.=5.31-5.81. Composition, Ag 69.28, Br 14.30, Cl 16.42; the relation of the chlorine to the bromine may vary indefinitely. Pyr. &c,. B. P. Acts like Cerargyrite, but gives the reaction for Bromine. 12 178 LECTURES ON MINERALOGY. It is found associated with Cerargyrite and Bromyrite generally as a coating, which has sometimes a columnar structure. FORMULAE OF THE CRYSTALS. Pi. XXXIV.' Ilg. 8. oooo. Fig 1. cooo. 0. Fig. 12. oo0. cooo. Ilodyrite. Ag I. HEXAGONAL. SYN.-Iodic Silver, Iodsilber, Iodit, Iodargyrit, Iodure d'argent. The crystals are quite small and rare. Cleavage perfect, parallel to the base. Lustre, adamantine, resinous. Translucent. Color, sulphur-yellow, canary-yellow, sometimes greenish or brownish. Streak, yellow. In thin plates it is flexible and sectile, but in masses it is brittle. H.=1-1.5. G.=5.5-5.71. Composition, Ag 46, I 54. Pyr. &c. B. P. In a closed tube, fuses and is orange-yellow while hot, but resumes its color on cooling. - Fuses in the flame of a candle. On Ch., gives fumes of iodine and a globule of silver. It is usually compact, with a more or less lamellar structure. It has been found in Arizona. GOLD. Gold. Au. ISOMETRIC. SYN. —Gediegen Gold, Or natif. It is found crystallized in cubes, octahedra, tetrahexahedra and rhombic dodecahedra. Sometimes faces of the tetragonal trisoctahedron and hexoctahedron may be observed. The octahedron is sometimes hemitrope or hollow and the crystals are often rounded. Lustre, metallic. Color and streak, different shades of yellow. Ductile, malleable. H.=2.5-3. G.=15.16-19.34. Composition, when pure, Au, but generally it contains traces of other metals. Pyr. &c. B. P. Fuses easily, but gives no reactions with fluxes. Soluble ii aqua regia. Native Gold has all the characters of ordinary gold; it is sometimes of a light tint, because it is alloyed with silver or lead. It is found in wiry masses, made up of chains of octahedra or cubes joined together, resembling those of Native Silver. It is also found in thin sheets or dendrites on the surface of some rocks. The ordinary gangue of Gold is Quartz, but it is also found in slates and metallic sulphides. It is not combined with them, but is in the native state in little pellets. The sulphides are the gangue of the Gold as the Quartz sometimes is. The rocks which contain Gold, have often become decomposed and broken up, and the products of this alteration have been washed out, thus forming the alluvial:auriferous sands. The scales in these sands are flattened, the size of the scales depending on the condition of the Gold in the vein. When these sands are treated for Gold by washing, the scales are easily separated, on account of their high density. The large rounded fragments found in rich sands are called nuggets. Some of these nuggets are of considerable size. The following table gives the weights of a few of the principal ones. LECTURES ON MINERALOGY. 179 Weight. Weight. lbs. oz. lbs. Welcome Nugget, 184 8 Miask, Urals 27 Ballarat, Australia, -" It 16 value, $41,822 Paraguay 50 Blanch Barkley Nugget, 146 Cabarrus Co., N. C., 37 Miask, IJrals 96 California 27 " " 27 " 17 In the Eastern states Gold has been found principally in Virginia, N. and S. Carolina, and Georgia. FORMULYA OF THE CRYSTALS. P1. XXXIV. Fig. 13. 0, with cavernous faces. Fig. 14. oo 0 2. Fig. 15. 3 0 3. 0. Fig. 16. coO. 0. 402. Fig. 17. 0. ooO; flattened parallel to a face of the octahedron. PLATINUMI. Platinum. Pt. ISOMETRIC. SYN.-Platina, Platin. When crystallized it is found in cubes and octahedra. Fracture, hackly. Lustre, metallic. Opaque. Color and streak, steel-gray. Streak, shining. Ductile, occasionally showing polar magnetism. I. =4-4.5. G.=16-19. Composition, Pt. combined with iron, iridium, osmium, and other metals. Pyr. &. Be.. P. Infusible and gives no reactions with the fluxes. Soluble in aqua regia. Its density is very great, but is less than that of Platinum which has been worked. It is between 16 and 19, while that of worked Platinum is 22. In nature, Platinum is very frequently associated with other metals, which are rarely, if ever, found except associated with it, such as palladium, rhodium, iridium and osmium. The ores of Platinum have sometimes been found in place in Serpentines and Syenites. It is disseminated in these rocks either as little grains, or masses, which are more or less large. The largest found weighed 21 lbs. In the collection of minerals at the School of Mines, Columbia College, there is a mass weighing 22.5 ozs. These masses have a metallic lustre, and the grayishwhite color, peculiar to Platinum. Sometimes this mass is quite brilliant, but it is always more or less cavernous or filled with holes, which sometimes go completely through it. Sometimes it is quite black. The color varies with the place where it i~ found. In Russia it is found black and white. In California it is white and brilliant, while that from Oregon is darker. Besides the ores in place, which are quite rare, it is frequently found in sands, produced by the wash of the altered rocks which contained it. These sands contain not only Platinum and the metals which accompany it, but Magnetite, Hematite, Menaccanite and Chromite, and are more or less auriferous, because Pyrite containing gold is often found in it. The minerals found with Platinum vary with the locality. They can be very nearly separated from it by mechanical preparation. They are known by the following characters. Platinum is found in small irregular grains, which are more or less flattened and tin-white. Palladium is in small grains more or less rounded, with a radiated fracture, which can be easily seen. These grains look like silver. These two are soluble in aqua regia, 180 LECTURES DON MINERALOGY. while the others are not. The residue from the acid is made up of grains which are bent, and contain rhodium and iridium. In these grains some crystals can- be distinguished, which have two parallel faces, with a regular hexagonal contour and a grayish color. These are Iridosmine. Ruthenium was found in these grains of Iridosmine, in the proportion of about 2 %. The ores of Platinum usually contain Pt. 90 %, insoluble residue 10 I, in which i % is Iridosmine, and 2 %Ruthenium. All of these substances are infusible except in the oxyhydrogen flame. IRIDIUM. Iridosmine. Ir, Os. HEXAGONAL. SYN.-Osmiridium, Newjanskit, Iridosmium, Sisserskit, Osmiure d'iridium. It is usually found in hexagonal tables, rarely as hexagonal prisms, with the basal edges modified. Lustre, metallic. Opaque. Color tin-white or steel-gray. Malleable with difficulty. 1H.=6-7. G.=19.3-21.12. Composition, Ir 43-70, Rd 0.63-12.3, Pt 0-2.8, Ru 0-8.49, Os 17.2-48.85. Pyr. &e. B.- P. At a very high temperature, gives off fumes of osmium. With nitre gives the reactions for osmium. It is found generally in irregular, flattened grains. In this country it is found principally in California. FORMULAE OF THE CRYSTALS. Pl. XXXIV. 1#ig. 18. o P. OP. Big. 19, oC P. P. OP. INDEX. Page Page Page Acadialite, 76 Alunogen,.. 110 Antimoine sulfure Acerdese,... 132 Amalgam,.. 173 plumbo-cupriAchirite,... 69 Aimalgam natif, 178 fWre,... 148 Acicular bismuth, 155 Amazon Stone, 53 Antimonblende, 160 Aciculite,.. 155 Amethyst,.. 16 Antimonbluthe, 159 Acide Boracique, 14 Amethyst oriental," 108 Antimonglanz,. 160 Acide Carbonique, 14 Amianth,... 31 Antimonite,.. 160 Actinolite, 29 Amianthus,.. 31 AntimonsilberActinote,.. 29 Ammonium,. 86 blende,.. 175 Adular,.. 53 Ammoniaque, Antimony,.. 158 Adularia,... sulfate, 86 Apatite,.. 95 Agalmatolite, 79 Amphibole,. 28 Aphanyte,. 31 Agate,.. 18 Amphigene,.. 48 Apherese,.. 169 Aikinite,... 155 Amphodelite, 50 Aphthitalite,. 82 Alabandine,. 134 Analcime,.. 75 Aplome,... 37 Alabandite,. 134 Analcite,... 75 Apophyllite,.72 Alalite.. 23 Analzim,. 75 Aquamarine,. 32 Alaunstein,. 111 Anatase,... 145 Aragonite,.. 96 Albine, 72 Andalusite,.. 61 Argent antimonie Albite,.. 52 Andradite,.. 37 sulfure,.. 175 Alexandrite,. 113 Anglesite,.. 149 Argent chlorure, 177 Allochroite,.. 37 Anhydrite,.. 91 Argent corne,. 177 Almandine, 36 Annabergite,. 139 Argentite,.. 174 Almandite,. 36 Anorthite,. 50 Argent natif,. 173 Alum,. 111 Anthophyllite, 28 Argent rouge anAlumine fluatee Antimoine natif, 158 timoniale,. 175 alcaline,. 112 Antimoine oxid6, 159 Argent rouge arAlumina Phos- Antimoine oxide senicale,. 175 phatee,. 113 octae'drique, 158 Argent sulfure',.174 Aluminite,. 110 Antimoine oxide Argent sulfure Alumnium,.. 108 sulfire,.. 160 fragile,.. 176 Alumocalcite, 20 Antimoine sulfure, 160 Argiles a porceAlumstone,. 111 Antimoine sulfure laine,.. 58 Alunite,.. 111 nickelifere, 139 Arkansite,.. 145 12* 182 INDEX. Page Page Page Arragon spar,. 96 Bergkrystall, 14 Braunspath,.. 102 Arseneisen,.. 125 Bergleder,. 31 Breccia,... 20 Arsenic,... 156 Beryl,.. 32 Bromit,... 177 Arsenical pyrites, 125 Berzeline,. 48 Breunnerite,.. 106 Arsenic natif, 156 Biaxial mica, 44 Brittle silver ore, 176 Arsenic oxide,. 156 Bieberite,. 136 Brochantite,. 168 Arsenic sulfure Bimstein,. ~ 57 Bromargyrite,. 177 jaune, 157 Biotite,. 44 Bromic silver,. 177 Arsenic sulfure Bismuth,.. 154 Bromsilber,.. 177 rouge,.. 157 Bismuth glance, 155 Bromure d'argent, 177 Arsenige saure,. 156 Bismuthine,. 155 Bromyrite,.. 177 Arsenikalfahlerz, 166 Bismuthinite, 155 Bronzite, 25 Arsenikbluthe,. 156 Bismuth natif,. 154 Brookite,... 145 Arsenikkalkies, 125 Bismuth sulfur6, 155 Brown hematite, 119 Arseniksinter,. 126 Bismuth sulfure Brown ochre,. 119 Arseniosiderite, 127 plumbo-cuprifere155 Brown spar,. 102 Arsenit,... 156 Bismuth tellure, 156 Brucite,... 59 Arsenkies,.. 125 Bittersalz,.. 105 Brucite,... 105 Arsenolite,. 156 Bitterspath,., 102 Bucholzite, 63 Arsenopyrite,. 125 Black Jack,.. 140 Buclilandite, pt. 40 Arsenous acid,. 156 Black lead,.. 13 Buntkupferkies, 165 Arsensilberblende 175 Blatterzeolith,.78 Bustalnite, 2. 26 Asbest,... 31 Blaueisenerde,. 124 Asbestus,... 28 Bleiglanz,.. 146 Asbestus,... 31 Bleischweif,.. 146 Calaite,.. 112 Asbolan,... 133 Bleivitriol,.. 149 Calamine,.. 70 Asbolite,... 133 Blende,. 140 Calamite,1.. 28 Asparagus stone, 95 Blue iron earth, 124 Calamite,... 29 Atacamite,.. 168 Blue malachite, 171 Calcareous spar, 98 Augite,... 24 Blue vitrol,.. 167 Calcite,... 98 Auripigment,. 157 Bog manganese, 133 Calcium,... 91 Autunite,.. 161 Bog ore,... 119 Calomel,... 172 Aventurine,.. 16 Bohemian Garnet, 36 Campylite,.. 151 Aventurine,.. 51 B6hmischer Granet, 36 Capillary Pyrites, 138 Azurite,... 171 Bolopherite,.. 24 Carbon,... 8 Boracite,... 106 Carbonate of lead, 152 Baicalite,.. 23 Borax,. 85 Carbonate of lime, 98 Balas ruby,.. 108 Borazit,... 106 Carbonic acid,. 14 Baltimorite,.. 80 Boric acid,.. 14 Carnelian,.. 18 Bamlite,... 63 Bornite,... 165 Cassiterite,.. 142 Barite,.. 87 Boron,... 14 Castellite,.. 67 Barium,... 87 Borsiaure,... 14 Castorite,... 27 Baryte suflatee, 87 Borsaures natron, 85 Cat's eye,... 18 Barytocalcite,. 89 Baryte carbonat6e, 88 Celestin,... 89 Basaltische Horn- Botryolite,.. 66 Celestine,.. 89 blende,.. 30 Bournonite,.. 148 Celestite,... 89 Basanomelan,. 128 Brauneisenstein, 119 Cellular pyrites, 123 Bellmetal ore,. 143 Brauner glaskopfs, 119, Cerargyrite,.. 177 Bergkork,.. 31 Braunite,... 130 Ceruse,... 152 INDEX. 183 Page Pagre Page Cerussite,.. 152 Cinnabarite,.. 172 Cuprite, 163 Ceylonite,.. 107 Cinnamon Stone, 36 Cyanite,. 63 Chabasie,... 76 Clausthalite,. 149 Cyanosite,. 167 Chabasit,... 76 Cobalt,... 135 Cymophane, 113 Chabazite,.. 76 Cobalt arseniate, 137 Cyprine,. 39 Chalcanthite,. 167 Cobalt arsenical, 136 Chalcocite,.. 164 Cobalt bloom,. 137 Datholite, 66 Chalcolith,.. 162 Cobalt gris,.. 136 Datolite,. 66 Chalcophacit, 169 Cobaltine,.. 136 Dauphinite,.. 145 Chalcopyrite,. 165 Cobaltite,.. 136 Davyne,. 46 Chalcosine,.. 164 Cobalt Pyrites, 135 Demant, 8 Chalcotrichite,. 163 Cobalt sulfate',. 136 Derbyshire spar, 94 Chalybite,.. 127 Cobalt sulfur6,. 135 Desmine,. 77 Chaux carbonatee, 98 Cobalt Vitriol,. 136 Diallage,. 25 Chaux carbonatee Cockscombpyrites 123 Dialogite,. 135 magnesif6re, 102 Colophonite,. 37 Diamant,. 8 Chaux fluat6e,. 94 Columbite,.. 129 Diamond,. 8 Chaux phosphatee, 95 Common Mica, 44 Diaspore,. 109 Chaux sulfatee,. 92 Copiapite,.. 124 Dichroite,. 42 Chaux sulfatee Copper,... 163 Diopside, 23 anhydre,. 91 Copperas,. 123 Dioptase, 69 Chemical clays, 59 Copper glance,. 164 Disthen,.. 63 Chessy copper,. 171 Copper nickel,. 138 Disthene, 63 Chiastolite,.. 61 Copperpyrites,. 165 Dolomite, 102 Chloanthite,.. 136 Copper uranite,. 162 Dry-bone,. 141 Chlorastrolite,. 72 Cordierite,.. 42 Chlorbromsilber, 177 Corindon,.. 108 Earthy calamine, 142 Chlorite,... 81 Corneine,.. 31 Eau,... 1 Chlormercur,. 172 Corundum,.. 108 Ecume de mer, 80 Chlorobromide Crichtonite,.. 128 Edler granat, 36 of silver,. 177 Crocoisite,.. 153 Egeran,. 39 Chlorobromure Crocoite,... 153 Eis,... 1 d'argent, 177 Cryolite,... 112 Eisenapatit, 134 Chlorsilber,.. 177 Cube ore,... 126 Eisenblau, 124 Chondrodite,. 59 Cuivre carbonate Eisenbluthe, 96 Christanite,.. 50 bleut,.. 171 Eisenglanz, 117 Chromeisenstein, 128 Cuivre carbonate Eisenkies,. 121 Chrome mica,. 44 vert,... 170 Eisenspath,. 127 Chromglimmer,. 44 Cuivre chlorure, 168 Eisenpecherz, 134 Chromic iron,. 128 Cuivre gris,.. 167 Eisenrose,. 128 Chromite,.. 128 Cuivre hydrate Eisensinter,. 126 Chrysoberyl,. 113 silicifre,. 70 Eisenvitriol,. 123 Chrysocolla,. 70 Cuivre natif,. 163 Eisspath, 53 Chrysolite,. 33 Cuivre oxidule, 163 Eisstein,. 112 Chrosolite du cap,' 71 Cuivre pyriteux, 165 Elheolite,. 46 Chrysoprase,. 18 Cuivre pyriteux Elaolith,. 46 Chrysotile,.. 80 hepatique, 165 Electric calamine, 70 Cinabre,... 172 Cuivre sulphate, 167 Embolite,.. 177 Cinnabar,... 172 Cuivre sulfure,. 164 Emerald, 32 184 INDEX. Page Page Page Emerald nickel, 139 Fowlerite, 26 Grammatite,. 28 Emery,.. 108 Flowers of Silicia, 19 Grammatite,. 29 Epidote,... 40 Fluorite,. 94 Granat,... 35 Epsomite,.. 105 Fluor spar,. 94 Graphic granite, 55 Epsom salt,.. 105 Flussspath,. 94 Graphite,.. 13 Erubescite,.. 165 Fontainbleau Grauspiessglaserz, 160 Erythrine,.. 137 Sandstone, 19 Gray antimony, 160 Erythrite,.. 137 Franklinite, 116 Gray copper ore, 167 Essonite,.. 36 Fuchsite,. 44 Grenat,... 35 Etain oxide,. 142 Grenat resinite, 37 Etain sulphur,. 143 Galena,.. 146 Greenovite,.. 67 Euclase,.. 65 Galenite,. 146 Green carbonate Eugenglanz,. 176 Galmei,.. 70 of copper,. 170 Euklas,.. 65 Garnet. 35 Green vitriol,. 123 Euphotide,. 25 Gediegen anti- Grossul ire,.. 36 Euzeolith,. 78 mol,. 158 Grossular,.. 36 Gecliegen arsen, 156 Grossularite,. 36 Fahlerz,... 167 Gediegen blei, 146 Grunbleierz,. 150 False Topaz,. 16 Gediegen eisen, 1-14 Gyps,... 92 Faserkiesel,.. 63 Gediegen gold, 178 Gypsum,... 92 Fassaite,... 24 Gediegen kupFeldspar,.. 53 fer,... 163 Haarkies,.. 138 Feldspath,.. 53 Gediegen queck- Elaarsalz,.. 110 Felsite, 55 silber,.. 171 Halite, 84 Fer arseniate,. 126 Gediegen silber, 173 Halites,. 84 Fer arsenical,. 125 Gedigen sylvan, 7 Hard fahlunite, 42 Fer azure,.. 124 Gediegen tellur, 7 Hard opal,.. 21 Fer carbonate,. 127 Gedliegen wismut, 154 Harmotome,. 76 Fer carbure,'. 13 Gelbe arsen- Hartbraunstein, 130 Fer chromate,. 128 blende, 157 -Iartmanganerz, 132 Fer natif,... 114 Gelbbleierz,. 153 Hausmannite,. 130 Fer oligiste,.. 117 Gelbeisenerz, 124 Hauyn,.. 48 Fer oxide rouge, 1.17 Gyserit,.. 31 Haiiynite,.. 48 Fer oxydule, 115 Gigantolite,. 43 Haydenite,.. 76 Fer phosphate, 124 Glace,... 1 Heavy spar,.. 87 Fer spathique,. 127 Glanzbraunstein, 130 Hedenbergite,. 24 Fer speculaire, 117 Glanzeisenerz, 117 Heliotrope,.. 19 Fer sulphate, 123 Glanzkobalt, 136 Hematite,.. 117 Fersulphure' blanc 123 Glaserite,. 82 Hematite rouge, 117 Fer sulphure jaune, 121 Glaserz,.. 174 Hemimorphite, 70 Fer sulphure mag- Glauberite,.. 84 Heulandite,. 78 netique,. 120 Glaubersalz,. 83 Himbeerspath,. 135 Feueropal,.. 20 Glaucolite,. 45 Hollspath,.. 61 Fibrolite,.. 63 Glinkite,. 33 1Hornblende,. 28 Fiorite,... 20 Goethite,. 118 Hornblende,. 30 Fire opal,.. 20 Gold,.178 Horn mercury,. 172 Flint,.. 19 Gold Stone,.. 16 Iornsilber,.. 177 Float stone,.. 20 Gold Stone,. 51 H-or silver,. 177 Flos ferri,.. 96 Goslarite,. 141 I-Iumboldtite,. 66 INDEX. 185 Page Page Page Humite,... 59 Kalkspath,. 98 Laumontite,. 69 Hyacinth,.. 38 Kalksteries,. 98 Lazurstein,.. 47 Hyacinth quartz, 16 Kalkuranit,.. 161 Lead,.. 146 Hyaline quartz, 16 Kammkies,. 123 Leberkies,.. 123 Hyalite,... 20 Karneelstein,. 36 Lederite,. 67 Hyalosiderite,. 34 Kaolin,... 58 Lepidocrocite, 118 Hydrate de mag- Kaolinite,.. 58 Lepidolite,.. 45 nesie,.. 105 Kapnit,.. 141 Leucite,.. 48 Hydrophane,. 20 Karstenite,.. 91 Leucopyrite,. 125 Hydrogen,.. 1 Kastor,... 27 Lherzolyte,.. 25 Hydrozincite,. 142 Keramohalite,. 110 Libethenite,. 169 Hypersthene,. 25 Kermesite,.. 160 Lime alumina Kiesel,. 14 garnet,. 36 Ice, 1 Kieselguhr,. 20 Lime chromium Ichthyophthalmite, 72 Kieselkupfer,. 70 garnet,. 37 Idocrase,... 39 Kieselmalachit, 70 Lime-iron garnet, 37 Ilmenite,.. 128 KIieselmangan, 26 Lime magnesia aluIlmenorutile,. 144 KieSelsinter,. 20 mina pyroxene, 24 Indianite,.. 50 Kieselzinkerz,. 70 Lime magnesia Indicolite,.. 60 Kobaltbluthe,. 137 amphibole, 29 Iodargyrit,.. 178 Kobaltglanz,. 136 Lime magnesiaIodic silver,. 178 Kobaltkies,.. 135 iron-alumnia Iodine d'argent, 178 Kobaltmanganerz, 133 amphibole, 30 Iodit,.... 178 Kobaltnickelkies, 135 Lime-magnesia-ironIodsilber,.. 178 Kobaltvitriol,. 136 amphibole, 29 Iodyrite,... 178 Kochsalz,.. 84 Lime-magnesiaIolite,.. 42 Kohlensaure,. 14 iron-pyroxene, 23 Iridium,... 180 Koupholite,. 71 Lime-magnesiaIridosmine,. 180 Kreuzstein,. 76 pyroxene,. 23 Iridosmium,. 180 Krisuvigit,.. 168 Lime-uranite,. 161 Iron,.... 114 Kuboit,.. 75 Limonite,.. 119 Iron alumnia gar- Kupferblau,. 70 Linnmeite,.. 135 net,... 36 Kupferblende,. 166 Linsenerz,.. 169 Iron Glance,. 117 Kupferbluthe,. 163 Liroconite,.. 169 Iron lime py- Kupferglanz,. 164 Lithia mica,. 45 roxene,.. 24 Kupfergrfin,. 70 Lithionglimmer, 45 Iron pyrites,. 121 Kupferkies,.. 165 Lithionit,.. 45 Iserin,... 128 Kupferlasur,. 171 Lithomarge,. 59 Kupfernickel,. 138 Loxoclase,.. 53 Jacinth,.. 38 Kupferuranit,. 162 Luchssap'phir,. 42 Jargon,... 38 Kupfervitriol,. 167 Jasper,... 18 Kyanite,... 63 Macle,... 61 Magnesite,. 106 Kalialaun,.. 111 Labrador spar,. 51 Magnei' boratEe, 106 Kaliglimnmer,. 44 Labradorite,. 51 Magnesie carbonKalinite,.. 111 Lamperdite,. 133 atee,.. 106 Kalisalpeter,. 82 Lapis-lazuli,. 47 Magnesium,. 105 Kalisulphat, 82 Lasurit,... 47 Magneteisenerz, 115 Kalkgranat, 37 Laumonite,.. 69 Magneteisenstein, 115 186 INDEX. Page Page Page Magnetic iron ore, 115 Minium,.. 146 Niobite,.. 129 Magnetic pyrites, 120 Mirabilite,. 83 Nitratin,... 83 Magnetite,. 115 Mispickel,. 125 Nitre,.... 82 Magnetkies,. 120 Molybdanglanz, 162 Nitrum,.. 86 iMagnetopyrite, 120 Molybdanoker,. 162:Nordenskiol:dite, 29 Malachite,.. 170 Molybdate of Malacolite,. 23 lead,.. 13 Obsidian,.. 56 Mangaanblende, 134 Molybdenite,. 162 Octahedral copManganese,. 130 Molybdenum,. 162 per ore,. 163 Manganese alum- Molybdine,.. 162 Octahedrite, 145 ina garnet, 37 Molybdite,.. 162 Odontolite,. 112 Manganese car- Monrolite,.. 63 Oisanite,... 145 bonate,. 135 Morvenite,.. 76 Oligoclase,. 51 Manganese phos- MIoss agate,. 18 Oligoklas,. 51 phate,. 134 Mountain cork, 31 Olive copper ore, 169 Manganese sul- Mountain leather, 31 Olivenerz,. 169 fure,.. 134 Mountain paper, 31 Olivenite,. 169 ~Manganite,. 132 Mountain wood, 31 Olivine,.. 33 Mangankiesel, 26 Mullicite,.. 124 Onyx, 18 Manganspath,. 135 Muriazite,.. 91 Opal,... 20 Marcasite,. 123 Muscovite,.. 44 Operment,. 157 Marionite,. 142 Mussite,... 23 Ordinary clays, 58 Marmolite,.. 8G Or natif,. 178 Mascagnin,.. 86 Nadeleisenerz,. 118 Orpiment,.. 157 Mascagnite,. 86 Nadelerz,.. 155 Orthoclase,.. 53 Meerschaum,. 80 Natrolite,.. 74 Orthose,.. 53 Megabromit,. 177 Natrolith,.. 74 Osmiridium, 180 Melanglanz,. 176 Natron, 86 Osmiure d'iridum, 180 Melanite,.. 37 Natron-mesotype, 74 Ouvarovite,. 37 Melanterite,. 123 Natron salpeter, 83 Melinose,.. 153 Natfirlicher Pagodite,. 79 Menaccanite,. 128 schwefel,. 5 Paisbergite, 26 Menilite,.. 20 Nemalite,.. 105 Paranthine,. 45 Mennig,... 146 Nephelite,.. 46 Pargasite,.. 30 Mercure chlorure, 172 Newjanskit,. 180 Pargsite,... 28 Mercure natif,. 171 Niccolite,.. 138 Paulite,... 25 Mercure sulfure, 172 Nickel,. 138 Peacock ore, 165 Mercury,..171 Nickelantimon- Pearl spar,.. 102 Micaceous iron kies,.. 139 Pearlstone,.. 57 ore,... 117 Nickel arseniate, 139 Pechstein,. 56 Microbromit,. 177 Nickeline,.. 138 Pectolite,. 68 Microcline,.. 53 Nickel ochre,. 1'39 Pegmatolith,. 53 Miemit,... 102 Nickeloker,. 139 Pektolith,. 68 Millerite,.. 138 Nickelsmaragd, 139 Pele's hair,.. 56 Mimetine,.. 151 Nickelspiessglanz- Pericline,. 52 Mimetisite,.. 151 erz,.. 139 Peridot,.. 33 Mimetite,. 151 Nickel stibine, 139 Perlite,.. 57 Mime de fer lime- Nickel sulfur, 138 Perlspath,.. 102 neuse,.. 119 Nigrine,... 144 Perlstein,. 57 INDEX. 187 Page Page Page Petalite,... 27 Proustite,.. 175 Rossolite,.. 31 Petrosilex,. 55 Psilomelane,. 132 Rothbleierz,. 153 Phakolith,. 76 Pudding Stone, 20 Rothearsenblende, 157 Pharmacolite,. 96 Pumice,... 57 Rotheisenstein, 117 Pharmacosiderite, 126 Purple copper ore, 165 Rotherglaskopf, 117 Phenacite,. 35 Pycnite,.. 61 Rothhoffite,. 37 Phenakit,. 35 Pyrargyrite,. 175 Rothkupfererz,. 163 Phengit,. 44 Pyrgom,.. 24 Rothnickelkies, 138 Philipsite, 165 Pyrite,... 121 Roth ruschgelb, 157 Phosphate of lead, 150 Pyrite cuvereuse, 165 Rothspiessglaserz, 160 Phosphate of lime, 95 Pyrolusite,.. 131 Rothzinkerz,. 139 Physalite,. 64 Pyromac, 19 Rubasse,.. 16 Piedmontite,. 40 Pyromorphite,. 150 Rubellite,. 60 Pierre d'azur,. 47 Pyrope,.. 36 Ruby oriental,. 108 Pierre de labrador, 51 Pyrophysalite, 64 Ruby silver ore, 175 Picrolite,. 80 Pyrostibite... 160 Rutile,... 144 Pictite,.. 67 Pvroxene,... 22 Pinite,... 43 Pyrrhosiderite, 118 Sahlite,. 23 Pistacite,. 40 Pyrrhotine,. 120 Sal-anlmoniac,. 86 Pitchblende,. 161 Pyrrhotite,.. 120 Salt,.. 84 Pitchstone,.. 56 Saltpetre,. 82 Platin,. 179 Quartz,... 14 Salzkupfererz,. 168 Platina,.. 179 Quartzite,.. 20 Sammetblende, 118 Platinum,. 179 Quartzresnite,. 20 Sandstone,.. 20 Pleonaste,. 107 Quecksilber- Sanidine,.. 53 Plomb arseniate, 151 hornerz,. 172 Saphir d'eau,. 42 Plomb blanche, 152 Quicksilver, 171 Sapphire,.. 108 Plomb carbonate, 152 Quincite,.. 21 Sapphirine,. 18 Plomb chromate, 153 Sard,.... 18 Plomb molydate, 153 Radelerz,.. 148 Sardine Stone, 18 Plomb natif,. 146 Raseneisenstein, 119 Sardonyx,.. 18 Plomb oxid rouge,146 Rauschgelb,. 157 Sassoline,.. 14 Plomb phosphat6, 150 Raycolite,.. 53 Sassolite,. 14 Plomb seleniur6, 149 Realgar,... 157 Satinspar,.. 92 Plomb sulphat6, 149 Red hematite.. 117 Scapolite,.45 Plomb sulphur, 146 Red ochre,. 117 Scheelbleispath, 153 Plumbago,.. 13 Red vitriol,.. 136 Scheelin calcaire, 104 Polyadelphite, 37 Red zinc ore,. 139 Scheelite,.. 104 Polybasite,. 176 Reissblei,. 13 Scheelitine,.. 153 Porcelain clay, 58 Remingtonite, 137 Scheelspath,. 104 Porzellanerde,. 58 Rhwetizite,.. 63 Schiller spar,. 80 Potash Mica,. 44 Rhodochrosite,. 135 Sch6rl,... 60 Potasse Nitrate, 82 Rhodonite,.. 26 SchwarzererdkoPotasse Sulphate, 82 Rhomb spar,. 102 belt,.. 133 Potassium,. 82 Ribbon agate,. 18 SchwarzspiessPotstone,. 79 Ribbon jasper,. 19 glaserz,. 148 Prase,. 18 Richterite,.. 28 Schwefelkies,. 121 Prehnite,. 71 Rock salt,.. 84 Schwefelnickel, 138 Prochlorite,. 81 Rosenspath,.. 135 Schwerspath,. 87 188 INDEX. Page Page Page Schwerstein,. 104 Speglande eiseng- Tetartine,.. 5 Schwimmstein, 20 limmer,.. 117 Tetradymite, 156 Scorodite,. 126 Speiskobalt,.. 136 Tetrahedrite,. 167 Selenblei, 149 Spessartine,.. 37 Texalith,... 105 Selenite, 92 Spessartite,.. 37 Texasite,... 139 Sel gemme,. 84 Sphalerite,.. 140 Tharandit,. 102 Semeline, 67 Sphene,... 67 Thenarclite,.. 83 Semi-opal,. 21 Spherosiderite,. 127 Thulite,... 40 Senarmontite 158 Spherulite,.. 57 Tin,... 142 Sepiolite,.. 80 Spinel,... 107 Tinkal,... 85 Serpentine,. 80 Spinthlre. 67 Tin pyrites,. 143 Siderite,. 127 Spodumene,. 27 Tin stone,.. 142 Siderose,.. 127 Spreustein,. 74 Titaneisenstein, 128 Siegenite,. 135 Sprodglaserz,. 176 Titaneisen,.. 128 Silberamalgam, 173 Stannite,... 143 Titane oxyde,. 144 Silberglanz,.. 174 Staurolite.. 68 Titanic iron,. 128 Silberhornerz, 177 Staurtide,.. 68 Titanite,... 67 Silex, 19 Steatite,... 79 Titanium, 144 Silicon,. 14 Steinheilite,.. 42 Topaz,... 64 Sillimanite,. 63 Steinmark,.. 59 Topaze,. 64 Silver,. 173 Steinsalz,.. 84 Topazolite,.. 37 Silver glance, 174 Stephanite,.. 176 Torbernite,.. 162 Sisserskit,. 180 Stilbite,... 77 Tourmaline,. 60 Stibnite,... 160 Stilpnosiderite, 119 Traversellite,. 23 Sinaltite,. 136 Stolozite,... 153 Tremolite,.. 28 Smarad,. 32 Strahlzeolith,. 77 Tremolite,.. 29 Slmaradlite,. 28 Strahlstein,. 28 Tripoli,... 20 Smectite. 59 Strahlstein,.. 29 Tripolite,. 20 Smirgel,.. 108 Stream tin,.. 142 Triplite,... 134 Smithsonite, 141 Striegisan,.. 113 Troostite,.. 34 Smoky quartz, 16 Strontiane Tungstate of lead, 153 Snow,.. I sulphatee,. 89 Tungstate of lime, 104 Soapstone,. 9 Strontianite,.. 90 Turkis,... 112 Sodium,.. 83 Strontium,.. 89 Turquois,.. 112 Soft opal,.. Sulphate of iron, 123 Somnmite,. 46 Sulphur,... 5 Ullmannite,. 139 Soude boratee,. 85 Sunstone,.. 55 Uralite,... 28 Soude carbonate6, 86 Urane oxide,. 162;Soude muriatee'6, 84 Tabular spar,. 21 Urane oxydule, 161 Soude nitratee,. 83 Tafelspatlh.. 21 Uranglilmer,. 162 Soda nitre,. 83 Talc,.. 79 Uraninite,.. 161 Soude sulphatee, 83 Talkspath, 106 Uranit,... 161 Soufre,... 5 Tellure auro natif Uranium,. 161 Spatheisenstein, 127 ferrif~re,. 7 Uranpecherz,. 161. Spathic iron, 127 Telluric bismuth, 156 Uwarowit,.. 37 Spear pyrites, 123 Tellurium,.. 7 Specklstein,. 79 Tellurwismuth,. 156 Valentinite,.. 159 Specular iron, 117 Tennantite,.. 166 Verd antique,. 80 Speerkies,. 123 Terre a foulon, 59 Vesuvian,.. 39 INDEX. 189 Page Page Page Vesuvianite,. 39 White coccolite, 23 Zinc bloom, o 142 Vitreous copper, 164 White copperas, 141 Zincfahlerz,. 166 Vitreous silver, 174 White Vitriol,. 141 Zincite,.. 139 Vitriolbleierz,. 149 Willemite,. 34 Zinconise,. 142 Vivianite,.. 124 Williamsite, 80 Zinc oxyde,. 139 Wilnite,... 39 Zinc silicate,. 70 Wad,... 183 Wismutglanz,. 155 Zinc sulphate,. 141 Walkerde,. 59 Witherite,.. 88 Zinc sulphur6,. 140 Warringtonite, 168 Wolfram, 129 Zinc vitriol,. 141 Washingtonite,. 128 Wolframbleierz, 153 Zinkblende,.. 140 Wasser,... 1 Wolframite,. 129 Zinkbluthe,.. 142 Wasserblei,. 162 Wollastonite, 21 Zinksilicat,.. 70 Wassersapphir,. 42 Wulfenite,. 153 Zinkspath,. 141 Water,.. 1 Wurfelerz,. 126 Zinnerz,... 142 Wavellite,.. 113 Zinnkies,. 1. 43 Websterite,. 110 Xenolite, 63 Zinnober,.. 172 Weichmanganerz, 131 Zinnstein,. 142 Weissbleierz,. 152 Yellow Ochre, 119 Zinnwaldit,. 45 Weiss spiess- Zircon,...38 glaserz,. 159 Zaratite,... 139 Zoisite,.. 40 Wernerite,.. 45 Ziegelerz, 163 Zwieselit. 134 Wheel ore,.. 148 Zinc... 139 .4 CA, / V"r "~~~~~~~~~~- ~L~ /;J~~~~~~~~~~ / 1/i / k~~~B~~~~~~~~~~~~~~~~~~~~~~~~~ 7-1~~~~~~~~~- - -I c -F-F~ r I I / \;~~~~~~~~~~~~: Y t t ) N -,-.N- $; ma'@X~~~~~~~fl~2P ~ ~ ~; 4, -? * 2 &r Ir~~rt?- 7/ I lBN SE -./ —4 6 4. tv, r r-:` —-: —Z- -N 7~~~\ ~ A / 1-I~~~~~~~1 /~~~~~~~~~I /I I~ t N/17 II~ f i -r " -' - r - j'N N>.-~~~~ -~~~~b~~~J;~~~~~'P~ ~ ~ -' —-N~~~~~~~~~~~~~~~~~~~~~~~~~~~~ — ) —-~ ~ ~~~~-7- --— i — N — N- — N / J tI K~ I -' ~~~~~~~~~~~~~~~~~~~~'......'' 2 K-LpJ'. - T J~a~pne%, — N —NK7%~: ~ Cr ----- --'I - >t~~-N7/L-N:-NW~~->,/;,.- z? / h: —-. - 4,t".'~ -'-:-; I 1 I: "' /7 ~;'..' /f j: i1 / 1.N 16I ~~~O d~~~~~~ I'E~ ~~~I "",~i~ ~K - 4 ~~ ~~~~~~~~~~~~~- N — ii'~~~~~~~~~l N,,1 4,~,P ___ I~~~ ~P ~3~~ ~~~~~~~~~~~~~~.- -> Cs C' ~s I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~- -- ----- ~' I ~~~~~~~~~~~~~~~ I r- i 144~~~~~~~~~~~~~~~~~~~- 1 \ f -IC -- ~7 —- 4 ~~~~~~~~~~~~~~~t~~~~~~~~~~~~~~~~~~~~~~~~~~~II,~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~I r3'r? 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