THE NONMETALLIC MINEKALS. 



187 



The mineral occurs in gneiss in Sweden; with barite and siderite at 

 Miisen; in limestone with galena and dolomite at Mine La Motte, 

 Missouri, and with sulphides of iron and copper in chloritic schists in 

 Maryland. 



SYCHNODYMITE has the formula (Co, Cu) t S 5 , and yields sulphur, 

 40.64 per cent; copper, 18.98 per cent; cobalt, 35.79 per cent; nickel, 

 3.66 per cent; iron, 0.93 per cent. It is of a steel-gray color, metallic 

 luster, and has a specific gravity of 4.75. 



ERYTHRITE or COBALT BLOOM (Specimens Nos. 17698, 51909, 56463, 

 53096, and 67759, U.S.N.M.) is the name given to a hydrous cobalt 

 arsenate of the formula Co 3 As 2 O 8 -h8H 2 O, = arsenic pentoxide, 38.4 

 per cent; cobalt protoxide, 37.5 per cent, and water, 24.1 per cent. 

 It occurs in globular and reniform shapes and earthy masses of a 

 crimson to peach-red color associated with the arsenides and sulphar- 

 senides mentioned above and from which it is derived by a process of 

 oxidation. In Churchill County, Nevada, it occurs as a decomposition 

 product of a cobalt bearing niccolite. It is also found at the Kelsey 

 mine, Compton, in Los Angeles County, California; associated vith 

 cobaltite at Tambillo and at Huasco, Chile, and under similar con- 

 ditions in various p..rts of Europe. 



ASBOLITE, or earthy cobalt (Specimen No. 60993, U.S. N.LI.), is a 

 black and earthy ore of manganese (wad) which sometimes carries as 

 high as 30 per cent of cobaltic oxide. It takes its name from the Greek 

 ctfffioXaivG), to soil like soot. ROSELITE is an arsenate of lime, mag- 

 nesia and cobalt with the formula (Ca, Co, Mg) 3 As 2 O g , 2H 2 O, = arsenic 

 pentoxide, 51.4 per cent; lime, 28.1 per cent; cobalt protoxide, 12.5 per 

 cent; water, 8 per cent. It is of a light to dark rose-red color, hardness 

 3. 5 ; specific gravity 3. 5 to 3. 6, and vitreous luster. SPH^ROCOBALTITE 

 is a cobalt protocarbonate of the formula CoCO 3 , = carbon dioxide, 37.1 

 per cent; cobalt protoxide, 62.9 per cent. It is also of a rose-red color, 

 varying to velvet black. Hardness 4, and specific gravity 4.02 to 4.13. 

 It occurs but sparing, associated with roselite at Schneeberg in Saxony. 

 REMINGTONITE is a hydrous carbonate the exact composition of which 

 has not been ascertained. COBALTOMENITE is a supposed selenide of 

 cobalt. BIEBERITE, or cobalt vitriol, is a sulphate of the formula 

 CoSO 4 + 7 H 2 O. The color is flesh to rose red. It is soluble in water, 

 has an astringent taste, and occurs in secondary stalactitic form. 

 Pateraite is a possible molybdate of cobalt. 



Aside from the possible sources mentioned above, cobalt occurs 



