ALABAMA MICA DEPOSITS 11 



ported to be sheet mica ; that is cut, uncut, and splittings, 

 the output of the Canadian mines for the period 1906 to 

 1917, is approximately stated at 11 per cent, of the world's 

 production, averaging annually for that period about 357 

 short tons, with but small fluctuations. Very little of 

 the India mica mined is consumed locally. For the period 

 1912 to 1916, 81 per cent, of its output exported, went to 

 the United States, and 17 per cent, to" Great Britain. 



South American exports, negligible before the war, 

 have recently made notable advances chiefly in Brazil 

 and in Argentina. In Brazil, the mica deposits, located 

 fairly accessibly to railroads for transportation to port, 

 mainly in the adjacent and contiguous states of Bahia, 

 Goyaz, Minas Garaes, and Sao Paulo, have received re- 

 cent increased development, considerable amounts of mica 

 being recovered from them during the war period, com- 

 paring favorably as to grade with India mica, and run- 

 ning in size up to large plates 20 by 10 inches, with sup- 

 plies indicated as obtainable, 6 by 6 inches in size. The 

 interior Province of Goyaz, while much less accessible, 

 has been recently reported to contain very large deposits, 

 the natives having long used it for window panes. The 

 output of the Brazilian mines prior to 1913 was negli- 

 gible, amounting to less than 10 tons per year. Under 

 war stimulus however, and because of the excellent qual- 

 ity of the mica produced, its output has heavily increased, 

 amounting in 1917 to 106 tons, or nearly 3 per cent, of the 

 world's production, and 10 times its pre-war recovery. 



The proportion of Brazilian mica coming to the Unit- 

 ed States has always been large and is increasing, con- 

 siderable capital has been invested, and present produc- 

 tion may be maintained in spite of existing difficulties 

 due to serious lack of transportation facilities and of 

 efficient labor, and to unfavorable climatic conditions. 



The mica deposits in Argentina lie mainly in the re- 

 mote and difficultly accessible mountain provinces of 

 Cordoba and San Luis, and not having been competently 

 developed, shipments made have generally been of infer- 

 ior grade, known and classified as stained or spotted mica. 

 Recent shipments of muscovite have, however, included 

 some good clear sheet mica, the available percentage of 



