18 GEOLOGICAL SURVEY OF ALABAMA 



which will serve to show as to relative sizes the possibly 

 fair averages of sizes actually realized in most domestic 

 mine operations. 



Estimated production of Sheet Mica in the United States in 

 1918, by sizes. 



P (funds. 

 Punch v 1.175,000 



1 ^ by 2 inches 217,000 



2 by 2 inches 175,000 



2 by 3 inches 1 61,000 



3 by 3 inches 56,000 



3 by 4 inches 35,000 



Larger sizes 56,000 



Splittings ... 11,000 



1,886,000 



The percentage yield of cut mica according to use, ap- 

 plied to the 700,000 pounds of estimated production of 

 uncut sheet mica larger than punch, would represent ap- 

 proximately the following yield of domestic cut mica for 

 1918: 



Approximate yield of cut mica larger than ptuich in the United 

 States in If) 18. 



Pounds. 



Cut condenser mica 91,000 



Cut electric mica 84,000 



Cut stove mica 28,000 



Other cut mica 21,000 



Scrap from cutting 476,000 



700,000 



These quantities would represent a maximum, as the 

 700,000 pounds of mica include the 1% by 2 inch size, (too 

 small for condenser mica), and include also all grades 

 from the clear, to the heavily stained and spotted. The 

 91,000 pounds of condenser mica, may therefore be taken 

 as the approximate maximum annual quantity of that 

 grade that this country could produce under 1918 condi- 

 tions. It is easy to see that the domestic mica was not 

 then sufficient to supply the demand for condenser mica, 

 which amounted to many hundred thousand pounds in 



1918, and was expected to be nearly a million pounds in 



1919, if the military program had continued in full force. 



