ay 32, 1G Ing CORNELL UNIVERSITY LIBRARY SRINEERING LIBRARY iversity TN 933. G78 7919 ‘ii GOVERNMENT PUBLICATIONS Bem (with the’ under-mentioned exceptions) can be. purchased in the mntsiet thinned ws the first page of this wrapper. . Hydrographical Publications of the Admiralty are sold by J. D. Potter, _ , , Minories, London, Bul. i. ; Patent, Office Publications. are sold at the Patent Office, 25, Southampton Buildings, Chancery Lane, London, W.C.2. ae rf Ordnance Survey and Geological Survey Publications can be purchased from the Director-General of the Ordnance Survey, Southampton ; from. the Director, Ordnande Survey, Dublin; or, from, Agents in most of the . Chief Towns in the United Kingdom. They can also be ordered through - any Bookseller. Small Scale Maps are on sale at the following branches of. H.M. Stationery Office :—28, Abingdon Street, S.W.1; 37, Peter Street, . Manchester; 1, St. Andrew's Crescent, Cardiff; and 23, Forth Street, . Edinburgh ; and all Railway Bookstalls. | : ; : The Ministry of the Board of Agriculture is published on the 1st of each ~ month by the. Ministry, and is obtainable from 10, Whitehall , Place, ‘London, '8.W.1.' Illustrated, 96 pp. Price 6d. post free. © The following is a list of some recent Official Publications (all prices are net, and those in parentheses include postage) :— IMPERIAL MINERAL RESOURCES BUREAU. ‘Tse Mininac Laws oF THE British EMPIRE AND OF FOREIGN COUNTRIES. Votume I., Nuiceria.--Preliminary Matter; GENERAL ANALYSIS; Introductory; Definition of Minerals and Mineral - Oils; Prospecting: Prospecting Rights, Exclusive Prospecting - Licences; Mining: Mining Rights, Mining Leases; Ancillary licences; Fees, Rents, Royalties and Duties; Transfer and - ‘Surrender of Rights; Explosives; Registration; Machinery for the Settlement of Disputes; Employers and Employed; Penal Clauses ; Note on Ordinances relative to Land Tenure ; Prospect- ing and Mining for Mineral Oil; ORDINANCES, REGULATIONS AND © Notices ; The Mineral Oils Ordinance, 1914, The Mineral Oils _ Regulations; The Minerals Ordinance, 1916 (as amended by ~ Sec. 2 of IV.); The Minerals (Amendment) Ordinance, 1918; Regulations made under The Minerals Ordinance, 1916: The General Minerals Regulations, 1916 (as amended by Amending Regulations Nos. 11 and 16 of 1916; Nos. 1, 28, 24, and 36 of 1918 ; and No. 28 of 1919), The Safe Mining Regulations, 1917 ; The Mica Mining Regulations, 1917; The Coal Mining Regula- tions, 1918; The Wolfram Royalties Regulations, 1919;. The: Non-Ferrous Metal Industry Ordinance, 1919; Regulations made under the Non-Ferrous Metal, Industry Ordinance, 1919; The 35029 4 IMPERIAL MINERAL RESOURCES BUREAU. THE MINERAL INDUSTRY OF THE BRITISH EMPIRE AND FOREIGN COUNTRIES. WAR PERIOD. MICA. (1915-1919.) LONDON: PRINTED AND PUBLISHED BY HIS MAJESTY’S STATIONERY OFFICE. To be purchased through any Bookseller or directly from H.M. STATIONERY OFFICE at the following addresses: ImperiaL House, Kincsway, Lonpon, W.C.2, 2nd 28, AsinGcpon Street, Lonpon, S.W.1; 37, Perer Street, MANCHESTER; 1, St. AnpRew’s Crescent, CARDIFF; 23, Fortn’ Street, EDINBURGH ; or from EASON & SON, Lrp., 40 & 41, Lower Sacxvitte STREET, Dustin. 1922. Price 9d. Net. GT BIT Tmpeerat. INSTINMIE |, LONDON, 7N 933 6768 (919 5680539 do PREFACE. The following digest of statistical and technical information relative to the production, consumption and value of Mica will form a part of the volume or volumes on the Mineral Resources of the british Empire and Foreign Countries constituting the Annual Mineral Conspectus of the Bureau. In this, the first year of publication, an effort has been made to fill in, as far us possible, the hiatus due to the war in the publications relating to mining and metallurgical statistics. Tiabour, health and safety statistics have been omitted owing to. the difficulty involved in procuring reliable information for the war period, but in future issues these statistics will be included in respect of each year. Resort will also be had to graphical representation of statistics of production, consumption, costs and prices. a The weights are expressed in long tons, that is to say, the British statute ton of 2,240 Ib., und values in pounds, shillings and pence at par rates of exchange. Dr. F. H. Hatch, a Governor of the Imperial Mineral Resources Bureau, is Chairman of the Advisory Technical Com- mittee which has dealt with this work. (Signed) R. A. S. RepMAYNE, Chairman of Governors. 2, Queen Anne's Cate nee London, 8.W.1 November, 1921. (35020—19) Wt. 21216—85/826 1600 1/22 H.St. (7.S.Ps. 530.) G.36 CONTENTS PAGE. GENERAL ate a Si eke ate ida a8 ay sedi WORLD'S PRODUCTION ... ies as sa 8 tes oan OE BRITISH HKMPIRE— United Kingdom se ans aig uk Pe ies iin 3 East Africa Protectorate (Kenya Colony) a sine was ED Nyasaland... ‘Ate se 2a ea see sal gg 81D Rhodesia 256 as wee oa de te ati wee 12 Tanganyika Territory (formerly German Hast Africa) ... we 12 Union of South Africa se adi aon age aia aca AS Canada... 23s wg sa sie ss ss es -. 16 Newfoundland ne bes i Bas $8 sais wis 20 India ... a ah bas sae ss fe ad ve, 20 Ceylon ... eg as is sta ais re at eae? 22 Australia dit me sis an sie ee iia «. 23 New Zealand ... ae — ses ce Set i aoe 24 FOREIGN COUNTRIES— Norway wee sits es i ee ae iste we. 24 Rumania oa aa aaa ae as aa aes ve 24 Sweden aes ie ae ae sie 25 ies ie 24, Madagascar... ats a wes as aoe ts wis. 25 United States... ig Dis Pe eae tee ae van 25 Argentina we ae es ie es si se «=. 28 Brazil ... ss si 98 ae oe a Ms ww. 28 China ... hee ‘ee van ae ee eae 2 0 ws 30 REFERENCES TO TECHNICAL LITERATURE ... ae .. 380 ° 3 GENERAL. The micas are crystalline silicates of aluminium and other metals, notably potassium, sodium, magnesium and iron. They are characterized by a very perfect basal cleavage, in consequence of which they can be split into thin plates. These plates are highly transparent when free from iron and other impurities. They are very elastic and possess remarkable insulating properties. The chief commercial varieties are muscovite or potash mica and phlogopite or magnesia mica. Muscovite is the most widely distributed variety. It is usually colourless and transparent when in thin plates, and generally occurs as ‘‘ books’’ in pegmatite veins associated with granitic intrusions. Phlogopite, though sometimes white or colourless, is often of a brown colour and is then known as ‘‘ amber ’’ mica. The com- mercially important deposits of this mineral occur associated with rocks rich in magnesia, especially pyroxenites. Lithia mica (lepidolite) is utilized ax a source of lithia, and not on account of its physical propertics. The transparency of mica sheets is often destroyed by imperfect development or by impurities taken up during the process of crystallization. Such inelusions frequently appear as films between the cleavage plates. Muscovite is particularly liable to be ‘‘ spotted ’? and “stained ’’ by iron oxide and other impurities. Such stains often render the mica valueless for economic purposes, unless they can be removed during the pro- cess of splitting. The micas vary considerably in hardness. Even in the same sheet the edge-hardness and the face-hardness are very different. The edge-hardness of muscovite is greater than that of copper, while that of phlogopite is almost the same as that of copper. Hence phlogopite is employed in dynamo-electric machinery even although its electrical and heat-resisting powers are inferior to those of muscovite. Owing to the irregular mode of occurrence of mica, systematic mining operations are rarely possible. For the most part the mineral is mined or quarried by open-cast methods and the excavation abandoned when the visible supply is exhausted. Where true mining operations are possible, the work is carried out by hand drilling, just sufficient explosive being used to loosen the rock preparatory to removing the mica crystals by picking. The product is sorted and split into plates and roughly thumb-trimmed and graded on the mine, after which it is sent to works where the plates are further trimmed, graded, and split. Clear sheet mica commands a high price for stove and furnace doors, for gas-lamp chimneys and shades, and other purposes. The chief use of sheet mica, however, is for electrical purposes as an insulator. During the war it was used for gas masks. 35029 A383 e 6 Sheet mica is used largely as follows :— (1) For separating the commutator segments of dynamo- electric machinery. A soft mica is best for this pur- pose, as this ensures equal wearing of the copper segments and the mica separators. | Consequently phlogopite or a soft muscovite is in greatest demand for this purpose. (2) For electrical heaters and cookers, and for pyrometers. (3) Electrical condensers. (4) Sparking plugs and magnetos. (5) Washers, and insulation of bolts and screws generally. For all the above, as indeed for most other purposes, it is necessary that the mica should split easily. It should also be free from cracks and conducting inclusions. Sheet mica less than 2 by 4 inches is practically useless for the purposes specified. Discs and washers punched from mica sheets are also used in arc lamps and gramophones, and smaller ones in the sockets of incandescent lamps. Flexible mica-covered cloth and tape find various uses in electrical apparatus. Formerly only sheet mica measuring 2 by 4 inches and upwards could be readily marketed, and much material of smaller dimen- sions was sent to the waste dump. At the present time, owing to the method of building up mica sheets from thin plates of scrap mica suitably trimmed and cemented with shellac, the greater demand in the industry is for splittings less than 2 by 4 inches in size, which can be hydraulically compressed and cemented with shellac into sheets of any desired thickness or size, or moulded to various shapes. Such material, known as ‘* micanite,’’ has now largely replaced sheet mica in commutators, especially those of large machines. An important use of micanite is for the insulation of the conductors in high-tension alternators when sheet mica cannot be used. The micanite is made in large thin sheets and is wound round the conductor by means of special machinery, the insulation being completed by heating under pressure. Alternatively, tubes are made in a similar manner, and the conductors afterwards inserted. Micanite is largely used for marine switchboard insulators. The use of micanite is rapidly extending in the electrical industry ; and consequently the chief demand is for mica splittings, which are imported in large quantities from India and Canada. Ground mica pulverized from mica scrap is used for a variety of purposes, the principal of which is to impart a lustre to wall- paper. Only the finer grades passing 160 to 200 mesh screens are suitable for this purpose. Other uses for fine-ground mica are as a component of paints and as a lubricant. 7 WORLD'S PRODUCTION. At the outset of the period under review the chief mica- producing countries were the United States, India, and Canada ; compuratively small quantities were obtained from German East Africa (now Tanganyika Territory), Brazil, Argentina, and Madagascar. Throughout the war period numerous factors contributed to increased activity in the mica-mining industry, and many new producers came into the market. Germany was formerly a large consumer of high-grade sheet mica suitable for electrical purposes, and the closing of this market had a depressing effect upon the mica-mining industry generally. As the war proceeded large quantities of mica were required for munition purposes, and both the Allies and the United States obtained increasing quantities of sheet mica from Argentina and Brazil. The enemy powers, being shut off from the regular sources of supply, turned to Norway and Sweden for their requirements. In the latter country a considerable industry sprang up in the manufacture of electric insulating material from mica mined in the Bohuslin district, and it is expected that this industry will be permanently established in Géteborg. Before the war the exploitation of mica in Argentina was chiefly in German hands. Output was desultory and the industry could not be considered permanent. The high prices ruling throughout the war period for sheet-mica of good quality stimulated production, and in the latter years of the period important shipments of such mica were made to England, the United States, Italy, and Spain. Large sheets of mica are recorded from Finland, but difficulties of transport have militated against mining operations in that country. World’s Production of Mica. (long tons.) | Country. 1913.| 1914.) 1915. 1916. | 1917.} 1918.} 1919, | | Nyasaland (exports) 9 | 5 | 4 1) — | 4 Southern Rhodesia.. es _— - i= _— =i 5 Tanganyika Territory’ (ex- 109 45) — _— 17 129 orts ' ies a, South Africa —_— — 2 12 69 24 9 Canada 5 bes 986 | 531 | 372 |1,079 | 1,041 | 667 | 2,459 Ceylon (exports = = = = = 6 8 India ene : 3,124 | 2,025 | 1,520 | 2,735 | 3,128 | 2,998 | 2.955 Australia ave _ 4; — — 38} — i Norway (exports) » 25 32 21 24 38 65 94 Spain... = = = Srp 8 7 Sweden (exporta) . _— 1 10 25; 8 5 1 Madagascar .. 6 8 1 3 1 4 18 United States* 5,511 3,578 3,782 | 4,345 3,631 | 2,780 | | 3,599 Argentina (exports 6 — — 6 62} 169 Brauil c a , 10; 15 50 53. 95| 112! 152 { * Chiefly scrap mica. 33029 A4 8 BRITISH EMPIRE. The greater part of the high-grade sheet mica consumed in industry is obtained from countries within the British Empire. India produces most of the high-grade sheet muscovite consumed, while Canada possesses almost a monopoly of the phlogopite variety. In addition to these producing countries, South Africa, Brazil, and Australia have considerable resources of high-class mica. So great is the producing capacity of India, that little effort appears to have been made to utilize scrap mica, which is at present thrown on the dumps, and an enormous tonnage of this material is now available for the manufacture of mica-board (micanite) and ground mica. In view of the great importance attained by the micanite manufacturing industry in the United States, and the large quantities of valuable sheet mica now being produced in many South American countries, the value of the Indian scrap mica for grinding and mica-board manufacture should not he overlooked. United Kingdom.* No veins or other deposits carrying mica of economic value are worked in the United Kingdom. The so-called ‘‘ mica ’’ or ‘* mica-clay ’’ obtained as a by- product in the Devon and Cornwall china-clay works is really an inferior kind of china-clay, and should not be classed as mica. London has long been an important market for the sale of mica. The larger part of the Indian production of muscovite, and intermittent consignments of mica from all the chief mica- producing countries of the world, are shipped to this market. Before the war the mica was sold at auctions, which were held periodically; but during and since the war these periodical auctions have been discontinued. The prices of Bengal (Bihar and Orissa) mica in London during the period under review were very irregular, and it is not possible to give satisfactory yearly averages. Prices were largely increased: as a result of war conditions, and in addition to this the smaller sizes of sheets, which were previously discarded, came to be in great demand. The increase in value may be seen from a com- parison of the average prices of clear Government Standard mica in July, 1914, and January, 1918, as follows :— Grade. July, 1914. January, 1918. sd. Ss. d. 1 9 0 17 6 2 8 2h 16 0 3 7 9 12 0 4 , 4 73 9 0 5 2 92 5 0 6 6 3.40 After a period of much uncertainty in the mica market, and consequent irregularity of prices, the Government fixed the prices of the different grades and qualities of Bengal mica in J anuary,. 1918, as follows (for definition of size grades, see p. 21) :— * Annual Statements of the Trade of the United Kingdom. ‘POST “9 ON “pe “8% (serytyerb 19439) “g “ON "pe “se (OI) Gg “ON pa sp Op yop ce ‘soolid pextg—: sduraydg A 1 ' | : | ‘8218 parpurys QO oT | 6 : TL QO oT | € I ; 9 T | 6 oT / 9 6 « Oo -# (Quatmtadaao zy) prada 9 ‘on £6 1 € 1 6 oT o£ | OLE qb |) 4 F pRB ek oon iQ a MS a aa GON ce | 8a ' ee SF 9 g 99 |} 02 Rak 0 4 Gs ag t ON oo 1 ay § 0 ¢ 6 9 6 2 0 OF , 9 OF QO If 0 él a ba on ae GON 9 9 6 69 | 9 6 9 OL o SE | @ St 9 EI 0 91 me RE a 7 ON 9 ob | oot 06 | 0 6 | O & € I 6 FI? 0 ST 9 LI oy eS ae ee TON si | oO # 9 Ol 9 fr | 9 GI 4 91 0 LI oe 0 0B A RR ha a 0 €t 0 01 6 Il eT | & OF a LL £ 81 0 61 9 18 Ree) ee paiaiel es 0 eT 0 @l oO et 1 0 LT 0 8t | 0 6f 0 06 | O T@ 0 i os ee “ einedy “xog 9 LI QO GT 0 OT ! 0 04 | QO 14 9 GZ 9 &@ 0 & 0 oO€ aa ree no ptsads: wap oxy 8 8 | ‘pe | ps ‘ps D8 8 > 8 8 | | [ae a “pouleys “poureys “prepueys 2 “OTT AR ‘poyjods | “pouteys Uber “poureys -Ayyied | “Ie9[o qUOTAUIAAOS Ura at . 2 ¢ oR Ayes ae 4sni) Ire Aypend —-4rpene pug euTeys 2} WOUL Ee SOpRAs aziy JOS Pra Jesueq | pue 4 rey, AUT P PB SAOEY S85) Areurpio ' pug -Apyaeg D TP (osnoyerem xo ‘q[ Jed) “ST6L ‘Aspnup¢ utodf par hug fo saoiag uopuoT parig 10 Imports of Mica into the United Kingdom. Quantity (long tons) From 1913. | 1914. | 1915. | 1916. | 1917. | 1918. | 1919. British India 2,009 | 1,225 | 1,477 | 2,172 | 2,449 | 3,320} 2,951 Canada we ae 69 62 93 44 22 24 39 Other British Pos- 16 17 37 iT 2 237 47 sessions, Total from British} 2,094 | 1,304 | 1,607 | 2,223 | 2,473 | 3,581 | 3,037 Possessions. Germany ... sigs 49 _— _— — _— = — Tanganyika Terri-| — _— _— -— 40); — 36 tory. Portuguese East * * 11 15 — 2 35 Africa. e United States 45 92 218 81 33 tT 128 Argentina ... _— f _— _ 4 35 39 Brazil oa sae | 7 11 6 2 tT 11 Other Foreign Coun- 64 55 28 7 2 1 8 tries. Total from Foreign 158 147 268 109 81. 38 257 Countries. ToTaL... 2,252 | 1,451 | 1,875 | 2,332 | 2,554 | 3,619 | 3,294 ® Value (£). British India . |143,861 | 94,601 | 92,119 )197,970 |351,233 1603,348 | 535,271 Canada eve --| 8,957] 7,611) 6,061] 7,594) 5,805] 8,990] 12,052 Other British Pos-} 1,974] 1,189] 2,391 589 126 | 50,967) 9,532 sessions. Total from British /154,792 |103,401 100,571 |206,153 |357,164 |663,305 | 556,855 Possessions. Germany we | 3,442) — — = = — = Tanganyika Terri-; — — — — 10,000} — 5,400 tory. Portuguese East * % 792| 1,433; — 249) 5,846 Africa. United States 1,024) 2,547) 3,675] 2,291} 1,577 32] 6,314 Argentina ... _ 7) — — 1,336 | 12,516] 9,350 Brazil ie site = * 6,711] 3,156 887 40] 4,761 Other Foreign Coun-| 2,926} 9,274 279 927 461 373} 1,264 tries. Total from Foreign | 7,392] 11,828) 11,457) 7,807) 14,261 13,210 32,935 Countries. TOTAL... » 162,184 /115,229 /112,028 [213,960 [371,425 |676,515 | 589,790 * Included in Other Foreign Countries prior to 1915. + Less than 5 ewt. 11 Exports of Mica from the United Kingdom (Colonial and Foreign Produce). Quantity (long tons). To er ee pee i 1913. | 1914. | 1915. . 1916. | 1917, 1918. | 1919. i 3 ! = i Belgium 54 les _— — — — _ France 14 35 130 57 282 592 300 Germany 655 49h — — — = 155 Italy . ‘ _— 3 17 16 23 64 26 Netherlands. 75 = i = — _— — 138 Switzerland.. 148 94 | 38 34 15 oT. 108 United States 283 202 | 125 677 769 608 387 Other Foreign Coun- 9 127 29 11 151 68 166 tries. Total to Foreign) 1,238} 956) 339) 895 | 124 1,359 1,280 Countries. ; Total to British| 25 i3| 4| 24 3 3 8 Possessions. | TOTAL... 1,263 969 | 343 919 | 1,243 | 1,362) 1,288 Value (£). : I Belgium 7,108! — = = = — — France 2,746 5,148) 16,661] 24,861 | 62,527 148,230} 55,909 Germany 71, 864 | 56 1553 _ _— a _ 16,926 Italy... as ee — "446 | 1,853} 2,998] 3,972] 18,150] 8,077 Netherlands | 7,670 | _ — —_ — 25,112 Switzerland... a, w4° 7 7,227} 2,800] 2,768} 1,200] 2646 14, 132 United States wee) DA GIS 3h 319 29, 790 {114,463 156, 060 158, 189 139, 250 Other Foreign Coun- 2266 10, 900 ! 5; 089 2,953 13. 413] 15,059 35, 571 tries. | Total to Foreign 158,284 114,503 56,193 |148,043 [237,272 a4 274 204,977 Countries. | Total to British | ‘B24 2,321! 1,255} 3,187] 1,375 ne 5,290 Possessions. TOTAL... 168,608 [16,014 57,448 |151,230 |238,647 pee 300,267 East Africa Protectorate (Kenya Colony) .* The demand for mica during the war led to the Administra- tion undertaking the development of mica deposits in this colony. Mining was carried on at Sultan Hamid and on the slopes of Mount Kenya at Chuka. The output amounted to about 20 tons * Colonial Reports (Annual), No. 1073, East Africa Protectorate. 12 of rough mica in the year 1918-1919. Two tons of trimmed mica was sent to England. Development may be said to have reached a paying stage when, owing to the Armistice, the demand ceased. and mining was discontinued. Nyasaland.* Scattered surface deposits of mica have been worked in the South Nyasa, Upper Shire, and Dedza districts, but so far no deposits of any large size have been found. Rhodesia. + Muscovite occurs at many localities in Rhodesia. It has been found in books of large size in the. Tuli district near the Limpopo River, and in the Urungwe district in Mashonaland. Lepidolite occurs south of Umtali associated with tourmaline of various colours, also as compact aggregates in greisenized pegmatites in the Victoria, Belingwe and Salisbury districts. A new mica field was opened up recently in the Lomagundi district of Southern Rhodesia. The claims are mostly situated between the Mwami and Mwichi rivers, tributaries of the Angwa. The area over which the claims are scattered exceeds 40 square miles. The mica (muscovite) occurs as ‘‘ books ’’ in pegmatite veins. These ‘‘ books ’’ vary from 4 to 5 inches in length to. as many feet, but are mostly between 6 and 18 inches. They are seldom more than 6 inches thick, and frequently only half that thickness. The staining of the mica is pronounced at the surface, but diminishes at a depth of 10 or 15 feet. The deposits of mica are continuous rather than pockety, and are regarded as sufficiently extensive to serve as the basis of a regular mining industry. The only recorded output of mica during the period under review was five tons in 1919. Tanganyika Territory (formerly German East Africa). Important deposits of muscovite mica have been mined in the area of the Uluguru mountains of the Tanganyika Territory. The mineral occurs in pegmatite veins traversing a biotite- gneiss which shows considerable variation in structure and mineral composition. The colour of the mica varies from dark brown to brownish green, but the mineral is very clear when not * Colonial Reports (Annual), No. 832, Nyasaland, Report for 1913-1914. + S. Afr. Journ. Ind., 1918, 1 No. 8, 679, and 1 No. 15, 1416. Reports of the Secretary for Mines, 8. Rhodesia (Annual). The Geology of the Lomagundi Mica Deposits, by H. B. Maufe ; Short Rept., No. 10, 8. Rhod. Geol. Surv., 1920. + Report on Tanganyika Territory, covering the period from the conclusion. of the Armistice to the end of 1920; H.M. Stationery Office, London, 1921 Cmd. 1428. 13 obscured by interlaminar inclusions, and plates 3-inch in thick- Ness are more than usually transparent. Perfect sheets have heen obtained, free from injury caused by extraction from the rock, und ineasuring up to 4 feet by 2 feet, though usually they ure much smaller. Ata number of localities, however, the mica has been found to be too much stained or crushed to allow of profitable mining. The chief deposits are in the region bordering the River Mbukana, a tributary of the Mgeta, and in the districts to the north of Morogoro. Many other localities are known to carry good mica, but lack of transport facilities and unfavourable labour conditions have prevented the exploitation of these deposits. . In 1918, 1084 tons of mica, valued at £15,700, were exported from Tanganyika, and during the first seven months of 1914. 45 tons, valued at £6,800, were shipped. The bulk of these consignments was sent to Germany, a small quantity only being despatched to Zanzibar. ; Early in 1917 it was decided to exploit these mica deposits. The Uluguru mines were worked by a Mica Board under the military authorities until July, 1914, when a mica expert arrived from England. Seventeen tons were exported by the Mica Board, und up to March 31, 1920, when the mines were closed, 129 tons were exported by the Civil Administration, or a total of 146 tons in three years. No details of value have been received, but it was estimated that the total value was about £40,000, Union of South Africa.* There was no reported production of mica of any importance within the Union of South Africa before the war. During the period 1910-1912 a large number of syndicates and companies were at work on two mica fields near Mica Siding and Malelane, but the results were disappointing and this activity was short-lived. The failure to establish a mica-mining industry in South Africa was due mainly to the difficulty in finding a satisfactory market for the mica obtained, and the industry slowly declined until in the vear 1915 only the Leydsdorp Mica Mines remained in operation. A considerable sum of money was spent in develop- ing these mines and establishing an agency in London. but trading results were unsatisfactory and the operations ceased at the end of 1916. A revival of interest in the Transvaal mica deposits took place during the years 1917 and 1918. Systematic mining operations were begun at the Union Mica Mines in the Selati-Olifants River district, and in response to inquiries from the United States and * Mica, by P. A. Wagner; S. Afr. Journ. Ind., 1918, 1 No. 8, 670-684. Annual Reports of the Government Mining Engineer. Annual Statements of the Trade and Shipping of the Union of South Africa and of Southern and Northern Rhodesia, 14 Japan, trial shipments were despatched to those countries. Con- siderable quantities of the larger sizes of sheet mica were also consumed locally by the electric firms and power companies on the Rand and elsewhere, but the total recorded production of mica within the Union is as yet very small. In 1917 an attempt was made at Johannesburg to manufacture micanite sheets from scrap mica. The sheets made were tested with satisfactory results. The local demand for mica sheets and micanite in South Africa is small. During the seven years ending December 31st, 1919, the total value of the mica and micanite imported was £3,769. Transvaal.*—Important deposits of mica occur in the Leydsdorp division of the Pietersburg district of this province. The mineral is found in a well defined mica belt extending from the neighbourhood of Mica Siding on the Leydsdorp railway towards the Portuguese border, a distance of about fifty miles. The width of the belt is 2 to 4 miles. In this area systematic mining operations have so far been carried on in three localities, namely :—(i) the neighbourhood of Mica Siding; (11) the Union Mica Mines, about 25 miles east of Mica Siding; and (ii) the Malelane mica fields, situated near the confluence of the Malelane and Olifants River. Throughout these regions the mica occurs in numerous veins of coarse white pegmatite on the southern margin of the Palabora granite. Some veins have been found to have a length of several hundred yards, and a width of forty feet or so. The pegmatite is composed essentially of quartz, albite and mica, associated (especially at Malelane) with fluor-apatite, garnet, and tourmaline. - As arule the mica is a pale brown muscovite, but in the Malelane deposits the mineral is characterized by a pale .green colour. It occurs either as thin tabular crystals or as ‘‘ books.”’ Many of the latter are a foot in thickness, and have a diameter of five feet. The mica occurs within the vein either in irregular pockets or in highly inclined leads. The mica varies in quality. Many ‘* books ’’ consist of clear brownish muscovite free from flaws and of excellent splitting quality; others are badly flawed. Some have a mottled appearance due to the inclusion between the lamine of a blackish substance, the nature of which has not yet been determined. Careful tests have shown that this mottled mica has insulating qualities equal to the clear brown mineral. The green mica occurring at Malelane is softer than the brown variety and well adapted for armature work. The limits of the Leydsdorp mica belt have not yet been accurately determined. Mining operations have nowhere * Mica in the Hastern Transvaal, by A. L. Hall; Union of 8. Africa, Dept. of Mines and Industries, Geol Surv., 1920, Mem. No. 13. 15 ; extended to a greater depth than 50 feet, and nothing is known as to the behaviour of the mica veins at depth. Cape Province.—A small quantity of mica has been produced from muscovite deposits near Jackal’s Water in Little Namaqualand. The mineral occurs in quartz-felspar pegmatite veins associated with tantalite and bery]. Other parts of the province where mica is known to occur are the Prieska and the Gordonia districts. No systematic mica-mining has so far been carried out within the province. » Production, Sales and Shipments of Mica in the Transvaal. Production. | Sales and Shipments Year. Quantity Quantity ; Value (long tons). (long tons). (£). 1915... | not stated 2 150 i916 cas : 12 | 1,185 WIT) sss. a 69 4 877 ee 24 5 1,185 TOI9 oa st 9 3 369 | | Exports of Mica from the Union of South Africa (Domestic Produce). | Quantity (long tons). To Fae 1913, | 1914, | 1915, | 1916. | 117, 1918. | 1919. United Kingdom ... go) ae ag te a 7 Portuguese = East _— — = — — — 1 Africa. United States... —- oo 4 1 2 2 Japan nae se eh oe ee aed 3 3 Torau ao we, GS Oe, te —————— : --- i " i= saci ra Value (£). United Kingdom ... 149 — 115 | 1,389 | 110 907 757 ’ Portuguese East _— — = aS | pas sa 60 Africa. | United States swe — — —_— — , 270 127 205 Japan fs ois = — = a | 18 647 210 Toran... 149] — | 115] 1,389 | 398 | 1,681 | 1,932 : | 16 Value of Imports of Mica and Micanite into the Union of South Africa. Value (£). From 1913. | 1914. | 1915. | 1916. | 1917. | 1918. | 1919. United Kingdom ... | 142 243 411 530 431 191 503 Canada sist wie —_ ne ae 3 ==) |e es — India 2a .. | 138. 165 62 47 21 17 160 Austria-Hungary ... 9 — — oes = ae = France Bos 5 — — — 20 — _— Germany ... we. | 183 10 1 — aa — = Italy ee — — eee a 20 = = United State: 8 18 22 16 42 36 98 Brazil fea = as aS a 19 ae Japan ass = — oe = ee 203 Toran... .. | 485 431 496 § 596 534 263 964 Canada.* Canada ranks second as a world’s producer of high-grade mica. The mineral mined is almost entirely phlogopite, very little muscovite being produced. The occurrence of phlogopite deposits of economic value appears to be confined mainly to Canada, more particularly to an area of 520 square miles situated in the province of Quebec to the north of Hull, and in the townships of North Burgess and Loughborough in the province of Ontario. Mica-mining is one of the important mineral industries of Canada. Mining operations are carried out either by open-cast quarrying methods, or by shafts and levels. Formerly the deposits were worked by small syndicates in a wasteful and haphazard way, but many of the mines are now owned by larger companies, who develop the deposits in’ a systematic manner, and block out adequate reserves. The erection of well- equipped cutting and grading establishments in the mica districts is due to the initiative of these companies. The sizes of sheets produced vary widely, according to the nature of the deposits mined. * * Mica : its occurrence, exploitation and uses, by H. 8. de Schmid, Mines Branch, Carada, 1912. Reports on the Mining ‘Operations in the Province of Quebec (Annual). Reports of the Ontario Bur au of Mines (Annual). Annua) Reports on the Mineral Production of Cavada. Annual Statements on the Trade of Canada. 17 According to information supplied to the Bureau by the Mines Branch of the Department of Mines, Canada, the grading adopted for Canadian mica is by size as follows :— Grade. 1” x 1" containing 1 to 2 sq. in. of clear mica. Ut x 2" ” 2 ay 3 ” ” ” 1" x 3" ” 3 Ww 6 ” ” yw 2 x 3" ” 6 be 8 ay ” ” 2" x 4" yn 8 ” 15 " ” Ww 3" x 5" ” 15 ” 24 W ” ” 2 x 6" ” 24 ” 40 ” ” Bt A x 8" 4 40 ” ” ” The mica is marketed under the above grades as thumb- trimmed, knife-trimmed and thin-split. Knife-trimmed mica is thumb-trimmed material, the edges of which have been trimmed with a knife. Thin-split mica is mica that has been split down to a thickness of from 0°001 to 0°002 inch. The prices during the period under review of these various grades of mica, as sold by a prominent Canadian firm, were as follows :— Prices of graded Canadian mica (phlogopite) ($ per Ib). Thumb-trimimed mica. : : ; | Grade. 1913. 1914, 1915, 1916. | 1917. 1918. ' 1919. i | ' | 1” x 1" 0:07 0°09 ' 0:09 | 0°10 0-10 0-10 0-15 1 x 2" 0°12 0°14 0-14 0°15 0°15 0°16 0-20 1” x 3" 0-30 0°30 0-30 0°30 1-30 0°30 0°35 2” x 3" 0°50 0°50 0°50 0-50 | 0°55 0°60 | 0°75 2" x 4" 0°80 0-80 0-80 0°80 0-90 | 1:00 « 1-00 3” x 5” 0°90 0-90 0-90 a-90 1°50 1°50 ! 1°50 4” x 6" 1:20. 1°50 1°50 2-00 2°00 2-00 2°00 5" x 8" 1°50 | 2:00 2°00 2-00 2°50 2°50 | 4°50 Knife-trimmed mica. Add 20 per cent: to above prices for thumb-trimmed mica for same grades in knife-trimmed. Thin-split mica. ; ; t Grade. | 1913, | 1914. | 1915. 1916, | 1917, | 1918. | 1919. | | | 1 4 ‘ r x i} O80 030 | OBO | OSE + 0°83 | O-s0 | 0-49 vx 2"... 0°33 0°83 | 0-35 | 0-BK = 0°88 | Oe4n | 45 Te ess 0°35 0°38 Oroy : UFO DE OB es | | 1-00 | 1-00 (irades above 2” x 3” are not thin-split. 18 Generally, a deposit of fairly good quality should yield an average of about :— 50 per cent. of thumb-trimmed mica cutting 1” x 3” 30 2 » 29 2” 2? 2? 2 x 3" 10 22 ” ” ”? ” a? 2" x at 6 m or a ee oy es Br x 5" 4 aA a - i re ss 4" x 6” The larger part of the mica produced in Canada is exported to the United States and the United Kingdom. The outbreak of the war adversely affected the Canadian mica market. Within a short time after the commencement of hostilities, the demand fell to practically nothing; most of the mica mines shut down entirely, and those producers who had to sell their mica did so at a loss. These unfavourable conditions lasted during the first 18 months of the war. Improvement in demand commenced during the latter half of 1916, and the industry entered upon a period of. prosperity; prices ruled high, but the cost of labour and material continued to advance to such an extent that in 1918 many mines were unable to work at a profit and closed down. Quebec.—In 1913 the province of Quebec produced about 60 per cent. of the total output of mica in the Dominion, the remainder being obtained chiefly from Ontario. Throughout the period under review Quebec maintained the leading position, and by the close of 1918 about 80 per cent. of the Canadian production of mica was obtained from Quebec mines and quarries. Both muscovite and phlogopite occur abundantly, but. most of the mica mined is of the latter variety. Muscovite is produced on a small scale in many localities, notably in the Saguenay district, and in the counties of Ottawa and Berthier, where it occurs in pegmatite veins. One of the oldest, and at one time the most productive muscovite mines in the province, is the Villeneuve Mine near Villeneuve town- ship, where the mica occurs as large tabular crystals or ‘‘ books ”’ lying in parallel veins of pegmatite. The deposit is remarkable for the number of minerals containing uranium and rare earths which are found throughout the pegmatite. These minerals include monazite and pitchblende. In Berthier county muscovite is found in large crystals in a pegmatite vein varying in width from 36 to 52 feet. This deposit has been opened up at the Maisonneuve Mine. The pegmatite contains the uranium mineral samarskite in appreciable quantities. Muscovite of good quality is found in many other localities in Quebec, but has not been mined to any considerable extent. Some of the deposits are worked intermittently, but transport costs are generally too high to allow of muscovite mining in the province at the present time. The chief phlogopite-mining centres are situated within the townships of Templeton, Portland, Hull, and Wakefield, between 19 the valleys of the Liévre and Gatineau rivers The city of Ottawa (Ontario) and the adjacent township of Hull (Quebec) are the centres to which the output of the various mines is mostly shipped for trimming, grading, and marketing. Ontario.—There are two separate mica districts in this province. One of these, approximately 70 square miles in area, is situated in the townships of Loughborough and Bedford, with Sydenham as the mining centre ; the other, about 50 square miles in extent, is situated in North Burgess, the town of Perth being its mining centre. The usual method of mining mica in Ontario is by means of open pits sunk on pocket deposits. | When these pockets are worked out, or the quantity of the mica no longer warrants further work, the pit is abandoned and a fresh excavation is made at another hkely place. The Lacey Mine at Svdenham, however, has long been developed in a systematic manner. It is the largest producer of mica in the province and is one of the largest mica mines in the world. The mica, associated with pink calcite and apatite, occurs in pockets within fissures traversing a pale green pyroxenite. The deposit is remarkable for the num- ber of large-size crystals aggregated within the pockets. The Canadian authorities point out that, in considering the following statistics of production and value, due regard should be given to the fact that the condition in which the mica is despatched varies greatly at different mines. In some cases the mica is cleaned and trimmed, while in others it is in a rough- cobbed state, and the prices realized are therefore far from uni- form. Moreover, the estimated value of consignments from mines and trimming shops may be merely nominal. Marketed Production of Mica in Canada. Quebec. Ontario. Total. Year. Quantity Value* Quantity Value* antity Value* (long (£) (long (£) (long (£) tons). . tons). | . tons). ; 1913... — ae 559 | 26,143 427 14,337 986 | 40,480 1914 ... da Ss 220 13,082 311 9,639 531 | 22,721 1915... oe ss 194 10,498 178 8,649 372 19,147 1916 ... oats Ba 754 40,072 325 13,103 | 1,079 53,175 AQT ics a or 691 59,736 350 15,025 | 1,041 74,761 1918... ase ata 429 47,733 238 8,840 667 5B,573 AQI9. ss ies dei 2,169 45,508 290 11,531 | 2,459 | 57,039 * Values converted to £ sterling at the rate of 1 dollar = 4s. 2d. 20 Exports of Mica from Canada (Domestic Produce). Fiscal years ending March 81. Quantity (long tons). To - 1913. | 1914. | 1915. | 1916.) 1917.) 1918. | 1919. United Kingdom ... 67 65 56 53 49 4 35 Newfoundland _... — — — — —_— _— _— India a wee _— — 2 _— — 8 France See ss 2. 3 1 — 2 _— _— Germany ... Sis _ 17 1 _ _— = = Netherlands a — — — — — —_— _— United States za 336 231 320 333 548 531 300 Chile aes iis — — _— — — — — Tora a3 405 | 316 | 380 386 599 535 343 | Value* (£). United Kindom ... | 7,273 | 7,409 | 6,637 | 7,117 | 9,956 | 1,157 | 11,469 Newfoundland 25 —_ _— — —_— — 25 — India ee —_ — 127 —_— —_— —_— 401 France as as 515 832 83 — 367 — — Germany ... a — 2,682 135 _— _ = — Netherlands a —_ —_ 42 = moe _ = United States «+» | 58,763 | 32,520 | 38,350 | 40,571 | 79,529 | 93,939 | 65,125 Chile se — — — _— 18 — — ToTaL --- (66,551 | 43,443 | 45,374 | 47,688 | 89,870 95,121 | 76,995 * Values converted to £ sterling at the rate of 1 dollar = 4s. 207. * Newfoundland. Mica occurs frequently in Newfoundland and Labrador, and many deposits containing large sheets of high-grade mica have been reported. Hitherto, however, little or no mining has been done on these deposits, and definite information as to their economic value is lacking. India.* India has long been the chief mica-producing country. With the exception of a little phlogopite which occurs in Travancore, the whole of the mica produced in India is muscovite, and is generally known as “‘ ruby mica.”’ The mica occurs as “‘books’’ in pegmatite veins traversing schists and gneisses, the associated minerals being quartz, microchne, tourmaline, garnet, apatite and more rarely beryl, samarskite, pitchblende and monazite. * Rec. Geol. Surv. India (Annual). Sea-borne Trade and Navigation of British India (Annual). 2] The principal mining centres are the vreat Bihar mica belt, about 60 miles in length by 12 miles in width, traversing the Monghyvr, Hazaribagh and Gaya districts in the province of Bihar and Orissa; and the Nellore district in the Madras Presidency. Tn addition, there are areas containing muscovite mica in Ajmer- Merwara in Rajputana. The mining practice generally followed differs in the two principal areas. In Nellore, the deposits are worked by extensive open quarries as far as that can profitably be done without mechanical assistance. When mining operations become dangerous, or water level is reached, the pits are abandoned. In the Bihar mica belt, the majority of the workings have been carried on in a very primitive and unsystematic manner, the importance of strike and dip being ignored. The ‘‘ books ”’ of mica have mostly been sought for haphazardly, by means of narrow holes and tunnels, and all rock and water is lifted to surface by hand. In recent years, however, systematic mining has made considerable progress. During the war the Government made every effort to increiuse the output of Indian mica in order to meet the demand for munition purposes. Advice and assistance were given by the officers of the Geological Survey in established mining areas and in searching for new sources of supply. Promising deposits were found in the pegmatite veins occurring in the State of Udaipur, and arrangements were made for opening up this mica-bearing belt. Acting under the Defence of India Act, the Local Government took over and worked successfully two mica-bearing properties in Bihar. The mines were ‘developed directly by officers of the Geological Survey of India. The produce from the mines is sickle-trimmed and sorted according to quality as follows :— Ist quality clear. 1st ,, partly stained. Qnd_,, clear. Qnd_,, partly stained. Fair-stained. Ordinary-stained. Densely-stained. Black-spotted. The following are the principal standard sizes marketed :— Square inches. Extra Specials... as a a 60 to 70 Specials... 9 oe a wa 48 ,, 592 A.l a ase a i 42 36 ., 47% No. 1 ee ae ee a at 24 ,, 35% No. 2 14 ,, 232 No. 3 10 ., 132 No. 4 6 ,, 9% No. 5 8, 5f No. 6 1,, 2% 22 It is estimated that not less than 90 per cent. of the original mica of the pegmatites is lost during mining and dressing. opera- tions. Practically the whole of the mica produced in India is exported inthe form of block-mica and splittings. Up to the present, the large accumulations of waste mica in the different mining centres have not been put to any practical use. Micanite is manufactured only on a very restricted scale in India, in spite of the fact that this country possesses a monopoly in the production of shellac, the principal ingredient in the cement employed in micanite manufacture. Exports of Mica from India (Domestic Produce). Quantity (long tons). To 1918. 1914. | 1915. 196, | 1917. 1918. | 1919. 1,908 | 1,104 | 1,309 | 2,297 | 2,945 2,998 | 2,709 | United Kingdom ... | United States... 534 382 160 292 111 — 194 Other Countries ... 688 539 51 146 72 — 52 Toran ae 8,124 | 2,025 | 1,520 a8 ad 2,998 | 2,955 Value (£). United Kingdom ... 223,176 |131,435 151,717 258,156 |475,214 |625,271 | 528,422 United States ... | 68,050] 54,717) 25,571] 36,898) 27,078; — | 41,172 Other Countries ... 56,226 | 51,158; 6,659); 16,626) 6,351 — 6,038 Tora. a ee 237,310 183,947 311,680 |508,643 |625,271 | 575,632 | 1 Ceylon.* Phlogopite mica is known to occur in velns associated with the crystalline limestones of Ceylon. Prior to 1918, very little mica- mining was done, but early in that year inquiries from the Ministry of Munitions in England led to a renewal of interest in the industry. Samples of Ceylon mica were sent to England, where they found a ready market, and a scheme was arranged whereby the Government agreed to purchase the commodity on behalf of London importers. The Principal Mineral Surveyor in Seylon was placed in charge of the scheme, which included careful inspection and grading of the mica produced and the pay- ment in Ceylon of 75 per cent. of the value of the mica accepted, a commission of 5 per cent. being charged towards the expenses necessarily incurred by the Ceylon Government. Although hostilities ceased shortly after the scheme came into operation, * Colonial Reports (Annual). 23 inquiries from I.ondon showed that the demand for mica of the quality shipped was likely to continue; the scheme therefore continued in operation with the object of establishing the Cevlon mica industry on a firm footing. The phlogopite produced realized excellent prices, but, on account of the irregularity and small size of the deposits, the cost of production was found pro- hibitive, and, with one exception, the mica pits opened during 1918 and 1919 have been closed. According to the Colonial Report for 1920, the exports during that year amounted to 296 cwt., valued at 36,523 rupees. Australia.* Mica-mining is not an established industry in Australia. Some years ago, muscovite was mined in the McDonald Ranges of the Northern Territory. The mica obtained was of excellent quality, but transport charges were too high to allow of profitable mining. The only production recorded for South Australia during the period under review was in the year 1917, when,38 tons, valued at £337, were raised in the Hundred of Para Wirra. Deposits containing large crystals of mica are known to occur in pegmatite veins on many of the mining fields of Northern Queensland, notably on the Einasleigh River, to the south-east of Georgetown, and at Brookland, near Junction (‘reek, both within the Etheridge Goldfield. Since the year 1914 considerable attention has been directed ° to the mica-bearing deposits on Rifle Creek, a tributary of the Upper Leichhardt River, about 68 miles due west of Cloncurry. The mineral is reported to occur abundantly in a pegmatite vein from 10 to 12 feet in thickness traversing hornblendic and micaceous schists. Numerous other pegmatite veins occur in the locality, forming « mica-bearing belt several miles in extent, which has not been adequately prospected. Samples for examination have been obtained from the outcrops of these deposits, but no attempt appears to have been made to determine the character of the mica at depth. The samples examined were much stained with iron and clay, but they gave satisfactory results when tested. Some of the crystals obtained were, roughly, 9 inches square. In Western Australia lithia-mica occurs in the pegmatite veins of the Londonderry district, near Coolgardie. During 1915 and 1919 prospecting operations were carried out on these deposits. Clear white muscovite was worked on a small scale in the Lockver Range, on the Upper Gascoyne River. Sheets up to 8 inches square were’ obtained, but the average size of the mica produced was much smaller. Other deposits are situated at Mullalyup and Northampton, but these have not been worked. The only recorded production in Western Australia during the period under * Min. Rev., S. Austr. Dept. Mines, No. 28, 1918, pp 47-48. Mica, by B. Dunstan ; Queens. Govt. Min. Journ., 1920, 21, 421-424 24 review was 4 tons, valued at £323, in 1914, and a few hundred Ib., valued at £26 and £10, for 1915 and 1916 respectively. According to the Government Geologist of Papua, mica in flakes of 6 square inches area occurs on Normanby and Fergusson Islands, in that territory, and prospecting for the mineral in the Eabalidi district, on Fergusson Island, might lead to the dis- covery of supplies of commercial value. New Zealand.* Muscovite mica occurs at Dusky Sound, south-western Otago; and at Charleston, south of Westport. At the latter locality a pegmatite vein containing plates of mica up to 6 inches by 4 inches in area was quarried during 1911 and 1912, and three or four tons of mineral obtained. The deposit has since then been carefully examined, but the proportion of sheet mica was found to be too small to make mining profitable. FOREIGN COUNTRIES Norway. Previous to 1913 very little mica was mined in Norway, but throughout the war-period German demands for mica of good quality for munition purposes led to considerable activity in the Norwegian mica-mining industry. The mica deposits are confined chiefly to the Skutterud district on the south-west coast, where the mineral occurs as a rule in small green crystals aggregated in lenses within pegmatite veins traversing metamorphic rocks. Much of the mineral mined is worthless owing to the frequent inclusion of tourmaline, garnet and other impurities within the crystals. A peculiar characteristic of Norwegian mica is that the thickness of its cleavage plates is frequently lacking in uniformity. Rumania. It was reported recently that rich veins of mica had been prospected, and were being exploited, in the district of Mehedintz, Rumania. Sweden. | No details of the production of mica in Sweden are available. but the following table shows the exports for the period under review :— * N. Zeal. Journ. of Sci. & Techn., 1919, vol. 2, No. 1. } Staustisk Arsbok. ¢ Ww 5 Experts of Mica from Sweden. Quantity Value.* Year (long tons). (£) FOIS kx pes — 2 1914. a bes 1 265 IOUS: aig ue fs 10 3,861 1916... r no 25 3,132 LOU sie ae ee 8 2,586 1OIB oe 2d om 5 1,301 WGle., cate a 3 al 44> Madagascar. Mica occurs in the district of Fort Dauphin and at other localities in southern Madagascar, also near the north end of Lake Alaotra in the north-eastern part of the island. Most of the mica produced in the island appears to have been muscovite, but phlogopite of good quality is also obtained. * United States.+ The mica mined in the United States is almost wholly muscovite, occurring as irregular masses, sheets and lenses in pegmatite veins traversing metamorphic rocks. The principal mica-producing States are North Carolina and New Hampshire, but Virginia, South Dakota, Georgia, Alabama, Idaho and Colorado, in the order named, also produce consider- able amounts. The mica mines of North Carolina occur in three belts. One of these is in the mountain region north-west of the Blue Ridge, another along the Ridge, and the third in Piedmont Plateau south-east of it. The greater part of the production from these regions comes from small mines and quarries worked in an intermittent and desultory manner. A few mines are worked on a considerable scale and are equipped with pumps, hoists and machine-drills. The crude mica is sold at the mines partly in the rough (as erystals or blocks) or split, rough-trimmed and graded. Nearly all the larger companies dealing in mica have their plants at Asheville and produce both sheet and punched mica, the waste and scrap being sold to the grinding plants, where the mica is ground by the wet method. In New Hampshire, mica deposits have been worked in Grafton, Cheshire, Sullivan, Merrimack, Belknap and Coos counties. The quality of the New Hampshire mica is good and the product has proved suitable for both glazing and electrical purposes. * Values converted to £ sterling at the rate of 18-2 kroner = £1. + Mineral Resources of the United States (Annual). The Mineral Incustry (Annual). Foreign Commerce and Navigation of the United States. 26 A considerable amount of prospecting and development work was done during the war in the Thomaston mica-field, Georgia, where a high-grade mica was mined in important quantities. _ In normal times the United States has always relied on foreign imports for about 60 per cent. of its requirements of high-grade sheet mica for domestic requirements. For the best grades suitable for electrical purposes the proportion of imported sheets was considerably higher. Even under the stimulus of high prices and active demand during the latter years of the war period, the mica mines of the United States were unable to attain their pre-war output, and it is doubtful whether the country can supply the normal domestic requirements for these grades. The principal sources of foreign supply were India, Canada, Brazil and Argentina, smaller amounts being imported from Guatemala, Mexico, Japan and South Africa. Marketed Production of Mica in the United States. Sheet Mica. Scrap Mica. Total Total Year. Quantity | Value* Quantity | Value* Quantity | Value* |(long tons). (£). (longtons).| (£). (longtons).| . (£). 1913 ... 759 73,649 4,752 17,197 5,511 90,846 1914 ... 248 58,029 3,330 10,712 3,578 68,741 1915... 247 78,804 38,535 10,523 3,782 89,327 1916 ... 387 109,268 3,958 14,564 4,345 123,832 1917 ... 570 157,057 3,061 11,023 8,631 168,080 1918 ... 734 152,460 2,046 6,902 2,780 159,362 1919 ... 690 100,743 2,909 12,101 3,599 112,844 * Values converted to £ sterling at the rate of 1 dollar = 4s. 2d. Exports of Mica from the United States. Unmaoufactured. Ppa? actured. Total Year. Valne* Quantity Value* Value* (£). (long tons). (£). (£). 1913 133 2,953 10,002 12,955 1914... 209 4,822 5,781 10,603 1915. 24 1,066 7,066 8,132 1916... 28 947 15,443 16,390 1917 5t 640 14,878 15,518 1918 t x ie 15,527 1919 t tf tf 22,781 * Values converted to £ sterling at the rate of 1 dollar = 4s, 2d. + January to June, inclusive. + Unmanufactured and manufactured not separately stated. 27 Imports of Mica for Consumption into the United States. Sheet. ‘ Ground, i Cut and ~~ Potal Unmanufactured.f littings.t Year. uae Quantity | Value? . oo Quantity | Value* (£). (longtons).| (£). | , (long tons).) (£). | ! i 1913 914 156,477 39,985 130 yu 197,455 1914 161 35,123 95,168 181 852s: 131,143 1915 194 50,094 93,325 154 804 144,223 1916 314 87,887 | 134,600 162 712 = -:223,199 1917 293 86,421 | 211,288 42 218 . 297,927 1918 331 137,203 | 183,522 5 343 321,068 1919 dea 392 185,320 | 154,864 _— 2 340,186 * Values converted to £ sterling at the rate of 1 dollar = 4s. 2d. + Mostly trimmed sheets. ‘t Includes the Madras square-shaped uncut sheets. Imports of Mica (Unmanufactured) into the United States. (Fiscal years ending June 30.) Quantity (long tons). From e 1914, 1915. 1916. | 1917. 1918. | 1919.F United Kingdom ... 205 75 95 | 170 159 145 Onion of South Africa _ — —_ , = 1 2 Canada oS 303 227 317: 196 70 56 Newfoundland and —_ _— — 1 — Labrador. India ... 181 25 22 | 37 9 10 Germany 27 10 _— | _— _— Guatemala —_— 1 1 — 2 5 Mexico 2 _ = 1 10 Argentina _— — — | 10 23 60 Brazil _— 2 11 38 48 103 Other Countries 1 1 — — 1 1 ToraL ... Ses 719 341 446 | 451 315 392 Value* (£). United Kingdom ... | 38,793 | 22,752 | 33,915 58,462 | 75,001 | 101,051 Union of South Africa _— — — — 365 153 Canada ... | 25,997 | 14,475 | 16,632 | 17,168 9,437 8,169 Newfoundland and _— _— _— _— 371 — Labrador. India ... 31,842 6,504 8,103 | | 20, yee6 1,319 3,707 Germany 12,107 1,127 — = Guatemala 8 119 "995 _— 160 754 Mexico 70 — _— — 120 351 Argentina — _ — 2,194 | 6,084 | 21,907 Brazil 37 820 3,420 9,201 | 20,256 | 48,093 Other Countries 407 391 —_ 20 72 1,135 ToTaL-. 109,261 | 46,188 | 62,365 | 107,671 | 113,185 | 185,320 * Values converted to £ sterling at the rate of 1 dollar = 4s. 2d. + Calendar year. 28 Imports of Mica (Cut, Split and nes into the United States. (Fiscal years ending June 30.) Value* (£). From 1914. 1915. 1916. 1917. 1918. | 1919.F United Kingdom... | 10,180 | 15,333 | 38,730 | 73,240 | 115,867 | 49,352 Canada aus bs 8,848 | 28,479 | 44,863 | 67,926 | 70,459 | 80,613 India side .. | 41,911 | 27,407 | 11,644 , 59,728 | 12,256 | 19,052 Germany... ihe 4,120 2,935 139 — = pe Netherlands ... oa _ 1,553 — — _ a Norway ies ads — 1,115 751 _— — — Guatemala ... es 16 337 = 97 136 50 Mexico as aes _— _ ma 1,062 _— 742 Brazil ae ge — 210 318 | 2,181 8,211 8,403 Other Countries ag — 22 _ 380 78 1,083 1,652 Toran ... ... | 65,075 | 77,391 | 96,475 | 204,312 | 208,012 | 154,864 * Values converted to £ sterling at the rate of 1 dollar = 4s. 2d. + Calendar year. Argentina. Deposits of high-grade muscovite mica are mined in many provinces of Argentina, notably in San Luis, Cordoba, and San Juan. The chief mining areas are situated near La Toma in San Luis, and at Calamuchita in Cordoba. Both these districts pro- duced considerable quantities of good clear sheets during the period under review. In spite of the large number of known deposits, mica-mining is not an established industry. The mines are worked in a desultory and primitive manner, and much of the material exported is spotted and stained. Before the war the average annual production of sheet mica was about 7 to 10 tons. Much of this output was consumed by local electrical undertakings, only the inferior sheets being exported. Mica mining was practically suspended during the first three years of the war, but the high prices and strong demand ruling in Argentina during the later years of the period greatly stimulated the industry. In 1917, 70 tons of mica were produced, and there was an estimated output of 80 tons in 1918. The larger part of the mica obtained was exported to the United Kingdom and the United States, smaller quantities going to Italy and Spain. Brazil.* Numerous deposits of mica are known to occur in various parts of Brazil; but, in spite of the possibility of cheap exploitation, mica-mining i is in a somewhat backward condition in the country, * Comercio Exterior do Brasil. 29 and 1s chiefly confined to the States of Minas Geraes, Bahia and Govaz. Lack of adequate transport facilities hinders develop- ment, but the recent high prices have tended to counterbalance this drawback, and there was a steady increase in production during the, period under review. The mica occurs in decomposed pegmatitic veins and lenticles traversing schists. These veins vary in width from 20 inches up to 10 feet in thickness, and consist generally of kaolin, in which ‘“‘ books ’’ of mica are irregularly disseminated. The dimensions of these ‘* books ’’ average about 6 inches by 6 inches b\ 3 inches, but plates ranging up to 10 inches by 20 inches by 6 inches are not uncommon. The mica obtained is known as ‘‘ ruby mica.”’ It is cleaned and split into plates }-inch to }-inch in thickness. These are finally trimmed by the guillotine machine and packed for shipment. About 70 per cent. of the run-of-mine mica is flawed and useless. Grading of the mica has not always been carefully attended to, and the inclusion of flawed sheets in the shipments has detracted from the value of Brazilian mica in the London market. (on- siderable capital has been invested in the industry, and careful attention is now being given to the preparation and classification of the sheets to meet foreign requirements, Eeports of Mica from Brazil. Quantity (long tons). To Jae 1918 1914. | 1918. 16 | 1917, | 191s. | 1919, : < i | | United Kingdom ... 6 ast 11 6 | 2 4 France wwe — | 1; 12 11: 13 | Italy — — 260 3 1, 1 United States. | — | — 2! 31| 81; 120| Other Countries ... Lp = 1 _— 9 i “ f ToraL |, = | 30/88 | ee Value (£).* United Kingdom... | 1,364 3207 2752 | 1. 153 | ! 3.320 France se ssi _— _— 372,090 8,287. 4,622 Italy ae a — | Beep. 1897 | Due; (3,259 United States ... 33 — | 2,940) 8,778 ‘28 1993 | 54,143 Other Countries ... 299 —_— =| 79 — 4 230 ToraL ... | 1,696 — 482 14,896 33,681 TB O80 “84,450 | * Values converted to £ sterling at the rate of 1 Milrei= 1s. 4. 30 China. According to the re Year Book, 1919, p. 82, mica is found in China near Sungpan, N. Szechuan, and is available for export, the price quoted at Shanghai being about 5d. per Ib., but no statistics of export are available. REFERENCES TO TECHNICAL LITERATURE. GENERAL. The Mineral Industry (Annual). The marketing and manufacture of mica, by S. O. Fillion; Trans. Can. Min. Inst., 1913, 16, 394-400. Electrical conductivity of mica, by E. Branly; Comptes Rendus, 1917, 165, 450-455. Mica: Dominions Royal Corieniasten, Final Rept. 1918, pp. 434-435. Mica for condenser plates, by H. S. Spence; Mines Branch, Canada, Summ. Rept. for 1918, p. 51. Report on certain minerals used in the arts and industries: 4, Mica, by P. A. Wagner; S. Afr. Journ. Ind., 1918, 1, 670-684, The Mica Miner’s and Prospector’s Guide, by A. A. C. Dickson; E. and F. N. Spon, Ltd., London, 1919. BRITISH EMPIRE. SoutH AFRICA, The geology of the Lomagundi mica deposits, by H. B. Maufe; S. Rhodesia Geol. Surv., Short Rept. No. 10, 1920, 8 pp. Notes on some non-metallic minerals: mica; Rhodesia Resources Com- mittee, 1921, p. 126. The geology of the Murchison Range and district: the mica and corundum deposits south-east of Leydsdorp, at Malelane east of Palabora, and elsewhere, by A. L. Hall; Union of 8. Africa, Geol. Surv., Mem. No. 6, 1912, pp. 153-160. The Olifants River mica belt, by W. T. Hallimond; S. Afr. Min. Journ., 1915, pp. 343-344, Mica in the Transvaal, by W. T. Hallimond; Mining Mag., 1916, 14, 269-270. Mica in the Eastern Transvaal, by A. L. Hall; Union of 8. Africa, Geol. Surv., Mem. No. 13, 1920, 95 pp. and bibliography. East AFrica PROTECTORATE, TANGANYIKA TERRITORY AND NYASALAND. Colonial Reports, East Africa Protectorate (Annual), Report on Tanganyika Territory, covering the period from the conclusion of the Armistice to the end of 1920; H.M. Stationery Office, London, 1921, Cmd. 1428, p. 67. Die bergbauliche Entwicklung Mittelafrikas: der Glimmerbergbau in den Ulugurubergen, by F. Schumacher; Metall u. Erz, 1919, 16, 63. Colonial Reports, Nyasaland (Annual), CanabDa. Report on the mineral production of Canada; Mines Branch, Canada (Annual), Mica mining in Canada, by H. 8. De Schmid; Trans. Can. Min. Inst., 1913, 16, 371-393. 31 Report on the non-metallic minerals used in the Canadian manufacturing industries. by H. Fréchette; Mines Branch Canada, No. 305, 1914, pp. 57-61. Amber mica in Canada, by O. Bowles; Repts. on Minerals Investigations of U.S. Bur, Mines, June. Reprinted Can. Min. Journ., 1919, 40, 594. Investigations in Nova Scotia. by A. O. Hayes; Geol. Surv. Canada, Summ, Rept. for 1917, Part F, p. 32. Report on mining operations in the province of Quebec (Annual). Mineral deposits of the Ottawa district; the mica deposits at the Nellis mine, by J. Stansfield; Geol. Surv. Canada, Guide-book No. 3, 1913, pp. 111-113. Mineralogical exploration of East Templeton district, Quebec. by A. Ledoux; Geol. Surv. Canada, Summ. Rept. for 1915, p. 166. South-western portion of the Buckingham Map-area, Quebec, by M. E. Wilson; Geol. Surv. Canada, Summ, Rept. for 1915, p. 161. The mineral deposits of the Buckingham Map-area, Quebec, by M. E. Wilson; Trans, Can. Min. Inst., 1916, 19, 356-362. Report of the Ontario Bureau of. Mines (Annual). Mineral deposits near Kingston, Ontario, by M. B. Baker: Geol, Surv. Canada; Guide-book No. 2, 1913, pp. 123-130. North shore of Lake Huron, Ontario, by W. H. Collins; Geol. Surv. Canada, Sumin. Rept. for 1917, Part E, pp. 14-15, White mica occurrences in the Téte Jaune Cache and Big Bend districts of British Columbia, by H. S. De Schmid; Mines Branch Canada, Summ. Rept. for 1913, pp. 42-49. Mica at Téte Jaune, Cariboo mining division, by J. D. Galloway; Ann. Rept. Minister of Mines, British Columbia, for 1914, p. 56. Undeveloped mineral resources of the Clinton district, B.C., by L Reinecke; Can. Min. Inst., Bull. No. 90, 1919, p. 1048. INDIA. Records of the Geological Survey of India (Annual). The India mica industry, by A. Faison Dixon; Trans. Amer. Inst. Min. Eng., (1913), 45, 94-112. Quinquennial review of the mineral production of India, by T. H. Holland and L, L. Fermor; Rec. Geol, Surv. India. 1915, 46, 22-24, 179-187, and 1921, 52, 20-23, 194-206. Mica and micanite, by G. H. Tipper; Indian Munitions Board Industrial Handbook, 1919, pp. 382-385. Report of the Chief Inspector of Mines in Mysore (Annual). Department of Mines and Geology, Mysore State, io (Annual). Mineral resources of Mysore, by W. F. Smeeth and P. Iyengar; Dept. Mines and Geol., Mysore State, Gen. Series, Bul. No. 7, 1916, pp. 131-134, Report on quartz, graphite and mica occurring in the Mundakayam district, by I. C. Chacko; Ann. Rept. State Geologist Travancore, for 1093 M.E., (1919), p. 5. CEYLON. Reports of Inspector of Mines, Ceylon Administration Reports, 1918 and 1919. Annual Colonial Reports, Ceylon. AUSTRALIA. Queensland mineral deposits: mica, by B. Dunstan; Queens. Govt. Min. Journ., 1916, 17, 263-265; also Queens. Geol. Surv., Publ. No. 268, 1920, 11 pp. and bibliography. ° 32 Central Australia (mica at Hart’s Range, near Arltunga), by J. J. Waldron; Bull. Dept. Ext. Affairs, 1916, Melbourne. Report on the Trade of Australia for 1918, by S. W. B. McGregor; H.M. Stationery Office, London, 1919, p. 51. New ZEALAND. The geology and mineral resources of the Buller-Mokihinui sub-division, Westport division, by P. G. Morgan and J. A. Bartrum; N.Z. Geol. Surv. Branch, Bull. No. 17 (New Series), 1915, pp. 124-125. Chrome-iron ore, mica, and tungsten-ore in New Zealand, by P. G Morgan and J. Henderson; N.Z. Journ. Science and Techn., 1919, 2, No. 1, 47-49. FOREIGN COUNTRIES. MApAGASCAR. The occurrences of mica in south-east Madagascar; Min. Journ., 1920, 121, 790. Etude succincte sur les mines de Madagascar; Bull. Econ. de Madagascar, 1920, ler et 2iéme trimestres, p. 23. Unrtep STATEs. Ths mineral resources of the United States (Annual). Some deposits of mica in the United States, by D, B. Sterrett; U.S. Geol. Surv., Bull. 580-F, 1914, pp. 65-125. Our mineral supplies: mica, monazite and lithium minerals, by W. T. Schaller; U.S. Geol. Surv., Bull. 666, 1919, pp. 153-158. Mica in Idaho, New Mexico and Colorado, by D. B. Sterrett; U.S. Geol. Surv., Bull. 530, 1913, pp. 375-390. A preliminary report on the feldspar and mica deposits of Georgia, by S. L. Galpin; Geol. Surv. Georgia, Bull. 30, 1915, 190 pp. ARGENTINA AND BRAZIL. Development of Argentine mica industry, by W. H. Robertson; Commerce Repts., 1918, No. 190, p. 599. The mineral resources of Minas Geraes (Brazil), by A. F. Calvert; E. and F. N. Spon, Ltd., London, 1915, pp. 92-94. Korea. Mica in Chosen (Kored), by S. Kawasaki; Chosen Mineral Surv. Bull., 1916, 1, Part 2, Seoul. Imperial Mineral Resources Bureau—continual. Land Registration Ordinance, 1915 (as arnended by the Land Registration (An.endment: Ordinance, 1915, and the Jand Registration (Amendment) (irdinance, 1916); The Land and Native Rights Ordinance, 1916 (ag amended by the Land and Native Rights (Amendment) Ordinance, 1918), The Public I.ands Acquisition Ordinance, 1917 (excerpts from). The (rown Jiands Ordinance, V18 (excerpts from); The Explosives Ordinance, 1015; Reyulations imade under the Explosives Ordinance; Master and Servant Ordinance, 1917; Rezulations made under the Master and Servant Ordinance, 1917: The Arbitration Ordinance, 1914; Goverpinent Notice Telative to undertaking as to dedination of tin ore exported, Government Notice prohibiting prospecting for Coal; Index. (1920.) Price 16s. (158s. Old ). Votume I1., West Arnica (Tas Gotp Coast, ASHANTI, ‘Pik NORTHERN TBRRITORIS, AND SIERRA LBONB).—Prelioinary Matter; G(RENBRAL ANALYSIS OF THE LAW RELATING TO THE GOLD Ca\sT AND ASHANTI: Introductory; Definition of Minerals, Mine and) Mining: Concessions; Definitions and Certification — of Validity ; Prospecting, Mining, Dredging and Pumping Licences ; Rights and Duties of the Concession Holder: Royalties, Rents, Duties and Stamps; Termination, Cancellation, Surrender or Tapse of Concession or Licence; Survey; Registration , Explosives: Machinery for Settlement of Disputes; Dealing in Minerals and Mineral Oils; Employers and timploved. Penal Provisions and Penalties; J.\W RELATING TO THE NORTHERN TERRITORIES ; General Analysis: Licences, Application and Fees ; Prospecting Licence, Prospecting and Mining Options, Mining and Dredging Jucences; Restrictions on Riehts Conferred, Inspection and Survey, Boundary Disputes, Penalties; SIERRA Leong: Introductory, Detinition of Minerals and Mineral Oils; Concessions > Definitions and Certification of Validity ; Prospect- mgoand Mining Licences; Rights and Duties; Rovalties. Rents and Stamps: Termination, Cancellation, Surrender or Lapse of Concession or Licence; Registration; Machinery, for Settlement of Disputes; Penal Clauses ; Survey : Explosives; Employers ¢ od Emploved ; Indices. (1920.)) Price 15s. (las. 7d.). Vottme IIT., THE Traxsvaar. (In the press.) [Beto IMPERIAL MINERAL RESOURCES BUREAU, | REPORTS ON THE MINERAL INDUSTRY OF THE Britis EMPIRE AND ForgIcn CounrRIEs. (WaR Periop, 1913-19.) - Aluminium and Bauxite sie (1921) Price Od. Antimony... cg op CLOT) Arsenic a as ws. (1920) _ Asbestos... be ... (1921) Barium Minerals ... —_.,. (1921) Bismuth 3... ... —... (1920) Borates at ae ... (1920) Coal. Part I vai wy AIGDITS= * ~ Coal. Part II Chrome Ore: Chromium ... (1920) “Cobalt act ay ad COD Felspar .. ns ... (1920) Fluorspar we gee?) cow AUR Fuller’s Earth. °.., —_... (1920) Iron Ore Resources of the World. Parts I, IT’ and. TI Iron Pyrites and Sulphur sa Magnesite... ete *. (1920) “Manganese ne a (1921) Mica Be sae, He 7” a 4102D- Monazite 2... .-. (1920) d Nitrates 0 -..- 0... 1. (1920) Phosphates, on.” 9.0% o5 bee (981)? , Tals. 4 uF spe ae ae ARO) Tungsten ww ew (192) Zine ga) Statistical Buriat. {Prsduction, Imports and Exports) (1913-20) és 3s. -(10}d.) - Is. (1s. 14d.) 5 6d. (7d.) ai Is. (1s. 1d.) Lyte Oden. L050.) oe 6% ea » 9d. (03d.) », 88. 6d. (3s. 8kd.) v6 (in the press) ated “the, ee ae 9d. (103d.) ;; 6d. (7d.) 9d. (104d.) 6d. (7d.) 3 (in the press) - me O &. cae. Pe 2 » 1s. 3d. (is 45a) » 988. 6d. (8s. 83d.) a 9d. “ORG - és bd. “tid ~ » ‘9d. ~ (104d.) is Qs. (Qs. 1d.) — ce, Ode (ORG) ae Is. (1s. 13d.) » 88. 6d. (38: 8d.) . (88. 2d.) _