I.EOXHARD NOTES ON THE MINERALOGY OF MISSOURI. 447 



brown or brownish black color and earthy appearance, mostly in 

 lenticular masses, 1-20 inches thick. 

 Melanterite. 



As white efflorescence on old dumps and in old passages of coal mines; 

 and in the water of many springs. 



MANGANESE. 



PSILOMELANE. 



In Bollinger Co., massive, often in stalactitic forms, with Limonite. 

 Halsmannite. 



In Dent Co.-, in massive pieces. 

 Wad. 



In Bollinger Co., and at Stephens Coal Batik, Cooper Co. 



At Mine La Motte and Old Copper Miues, Madiso?i Co., in black earthy 



masses, containing Nickel, Cobalt and Copper. 

 Rem. — Manganese Ore, occurs in Iro7i Co., on Cuthbertson tract (as ses- 

 quioxyd, perhaps with binoxyd) and on Marble's land (as protoxyd), 

 mixed with more or less sesquioxyd of iron. 



ALUMINIUM. 



PiCKINOERITE. 



Kt McCarro-v's Coal Bank, Barton Co., observed by C. J. Norwood, 

 as white efflorescence, with silky lustre, on sandy shales of the Coal- 

 measures. In bands, 1-2% inches thick. It contains (analysis of R. 

 Chauvenet) : 



Sulphuric Acid 35-77 



Alumina 15-55 



Magnesia 2.92 



Water 44 64 



98.88 

 Lazulitk. 



At Pilot Knob. Iron Co., microscopic crystals of deep blue color, in Ser- 

 pentine. (Observed by A. V. Leonhard.) 



MAGNESIUM. 

 Dolomite. 



In St. Louis, in cavities of the limestone. Very frequently as a compact 

 lining of these cavities, of light pink color, wholly covered by Dolo- 

 mite crj'stals of the same color, with strong pearly lustre, in the usual 

 form of the rhombohedron, with curved or distorted faces. Single well 

 developed crystals are often wholly or partially enclosed in Calcite 

 crystals, or embedded in aggregations of Millerite crystals. 



At Granby, Newton Co., it forms the principal "gangue" in the Lead 

 and Zinc Ore deposits. Mostly in coarse crystalline bands, in dolo- 

 mitic limestone, associated with the ores, and covered with Dolomite 

 crystals. Color white, yellow, or yellowish-brown. 



In Cedar Co., in coarse crystalline bands of drab or light pink color, in 

 limestone. 



