THE NONMETALLIC MINERALS. 



173 



fju'tuiv of ptMK'ils or (•rucil)l('s. Tho average fornuila of the mixture 

 is: Grapliite, Sd jxirts; steatite, soapstone, or talc, 14 parts; alum, 6 

 parts; but this \aries with the purpose to which the material is to be 

 applied. When sevei-al ditt'erent kinds of graphite have to 1)e employed, 

 tiu^ richest iu carbon is first mixed into the alum solution. By this 

 process graphites previously regarded as incapable of being compacted 

 are utilized, and are improved in polishing power. For pencils the 

 material may be hard without being brittle, and black without being 

 soft, while crucibh>s made from the treated graphite are at once harder, 

 more durable, and lighter.' 



Prices. — The value of the mineral varies with its quality. In 1899 

 the crude lump was reported as worth $8 a ton and the pulverized $30. 



The annual output as given" for the principal countries is as follows: 



WorWs production of graphite. 



Year. 



1892. 

 1893. 

 1894. 

 1895. 

 189(5. 

 1897. 

 1898. 



Germany. 



Metric 

 Ions. 



4,036 



3,140 



3,133 



3. 751 



5, 248 



3,861 



4,593 



India. 



Metric 

 tons. 



(a) 

 (a) 

 1, 623 



(«) 

 (a) 

 61 

 22 



Italy. 



Metric 

 tons. 



1,645 



1,465 



1,575 



2,657 



3,148 



5,650 



6,435 



United 

 States. 



Metric 

 tons. 



707 



634 



349 



171 



184 



450 



824 



a Not reported in the Government statistics. 



b Exports. 



BIBLIOGRAPHY. 



J. W. D.\w,sox. On the Graphite of the Laurentian of Canada. 



Quarterly Journal Geological .Society of London, XXVI, 1870, p. 112. 

 M. BoNXEFOY. INIemoire sur la Geologie et 1' Exploitation des Gites de Graphite de 

 la Boheme ]Meridi<inale. 



Annales de.s Mines. 7th Ser., XV. 1879, p. 157. 

 John S. Newberry. The Origin of Graphite. 



School of Mines Quarterly, VIII, 1887, p. 334. 

 Der Ciraphitbergbau auf Ceylon. 



Berg- und Hiittenmannische Zeitung, XL VII, 1888, p. 322. 

 J. AV.\LTHER. Ueber Graphitgiinge in zersetztem Gneiss (Laterit) von Ceylon. 



Zeitschrift der Deutschen Geologischen Gesellschaft, XLI, 1889, p. 359. 

 A. P.\LL.\iscH. Die Graj)hitV)ergbaue ini siidlichen Bohnien. 



Berg- und Hiittenniannisches Jahrbuch, XXXVII, p. 95, 1889. 

 T. Andkee. Graphite Mining in Austria and Bavaria. (Al)stract. ) 



Journal of the Iron and Steel Institute, 1890, p. 738. 



1 Engineering and Mining Journal, LVIII, 1894, p. 440. 

 ' The Mineral Industry, VI, 1897; VIII, 1899. 



