ALABAMA MICA DEPOSITS 17 



ance or value, have been noted in an equal number of 

 other states. 



World production is altogether compiled and stated on 

 the sheet mica basis, for the reason that outside of the 

 United States, and in lesser degree Canada, the mica re- 

 covered, being almost altogether exported to some point 

 of manufacture, is clear sheet of good quality. 



In domestic production, no information is available for 

 comparison as to the precise amounts of such clear sheet, 

 owing to the fact that compiled statistics; which must 

 necessarily base upon such incomplete returns as mine 

 operators can be induced to furnish, make no separation 

 in amount in most cases between the various grades of 

 clear, defective, cut and uncut, punch, washer, and run- 

 of-mine, the gross amounts only being obtainable as re- 

 ported. 



In the report of the U. S. Geological Survey on Mica in 

 1918 by Waldemar T. Schaller, from which the statistical 

 and other data here given are largely quoted, compiled 

 statistics have received a most comprehensive and in- 

 structive analysis, in which upon an assumed (but indi- 

 cated as proven) basis, of a yield of one pound of cut 

 mica to every three pounds of uncut, the total production 

 for 1918 of uncut mica larger than punch, would approxi- 

 mate 700,000 pounds. 



An instructive and valuable determination by analysis 

 of the actual percentages of the different sizes of uncut 

 sheet mica entering into the above stated figure of total 

 production, is also made by Mr. Schaller in this 1918 re- 

 port, based upon an available aggregate amount of 150,- 

 000 pounds on which precise and accurate data had been 

 reported, these percentages applying only to uncut sheet 

 larger than punch, and working out as follows: 1% by 

 2 inches, 31 per cent; 2 by 2 inches, 25 per cent; 2 by 3 

 inches, 23 per cent; 3 by 3 inches, 8 per cent; 3 by 4 

 inches, 5 per cent; and of larger sizes, 8 per cent. 



Applying the percentages by sizes so obtained to the 

 estimated total production of uncut sheet, inclusive of 

 uncut punch, and reducing all cut mica to its approximate 

 equivalent (three times), of uncut mica, the following 

 important tables are further deduced by Mr. Schaller, 



