THE NONMETALLIC MINERALS. 



J. VOLNEY LEWIS. Valuable Discovery of Corundum. 



Canadian Mining Review, XV, 1896, p. 230. 

 The Corundum Lands of Ontario. 



Canadian Mining Review, XVII, 1898, p. 192. 

 Corundum in Ontario. 



Engineering and Mining Journal, LXVI, 1898, p. 303. 

 A. M. STONE. Corundum Mining in North Carolina. 



Engineering and Mining Journal, LXV, 1898, p. 490. 



229 



PISOLITIC BAUXITE. 



Bartow County, Georgia. 

 Specimen No. 63335, U.S.N.M. 



3. BAUXITE. 



Composition A1 2 O 3 .2H 2 O,= alumina, 73.9 per cent; water, 26.1 

 per cent. Commonly impure through the presence of iron oxides, 

 silica, lime, and magnesia. Color, white or gray when pure, but yel- 

 lowish, brown, or red through impurities. Specific gravity, 2.55; 

 structure, massive, or earthy and clay like. According to Hayes l the 



1 The Geological Relations of the Southern Appalachian Bauxite Deposits. Trans- 

 actions of the American Institute of Mining Engineers, XXIV, 1894, pp. 250-251. 



