COBALT AND NICKEL. 165 



Obs. From Joachimstahl, Przibram, Kiechelsdorf ; Sax- 

 ony ; Cornwall ; at the Sterling Mine, Antwerp, N. Y.; at 

 the Gap Mine, Lancaster Co., Pa.; at St. Louis, Mo., in 

 capillary forms, and sometimes wool-like, in cavities in inag- 

 nesian limestone. A valuable ore of nickel. 



Beyrichite has the formula Ni 5 S 7 . 



Smaltite. — Cobalt Glance. Chloanthite. 



Isometric. Occurs in octahedrons, cubes, and dodecahe- 

 drons, and other forms. See figs. 1, 2, 3, page 17, and 17, 27, 

 page 20. Cleavage octahedral, somewhat distinct. Also 

 reticulated ; often massive. 



Color tin- white, sometimes inclining to steel-gray. Streak 

 grayish black. Brittle. Fracture granular and uneven. 

 H. =5-5-6. G. = 6 -4-7 -2. 



Composition. (Co, Ni) As 2 ; the ore being either a cobalt 

 arsenide, or cobalt-nickel arsenide ; and graduating into the 

 nickel arsenide called Chloanthite. The cobalt in the ore 

 may constitute 23*5 per cent. ; but it may be wholly absent 

 as in the chloanthite. In addition, iron often replaces part 

 of the other metals, as in the variety Safflorite. 



In the closed tube gives a sublimate of metallic arsenic ; 

 in the open tube a white sublimate of arsenous oxide, and 

 sometimes traces of sulphurous acid. B.B. on charcoal, 

 affords an arsenical odor, fuses to a globule which gives re- 

 action for iron, cobalt, and nickel. 



Diff. Arsenopyrite (mispickel) has tho white color of 

 smaltite, but it yields sulphur as well as arsenic, and in a 

 closed tube affords arsenic sulphide, orpiment and realgar. 



Obs. Usually in veins with ores of cobalt, silver, and 

 copper. Occurs in Saxony, especially at Schneeberg ; also 

 in Bohemia, Hessia, and Cornwall. 



In the United States it is found in gneiss with copper 

 nickel (niccolite), at Chatham, Conn. 



Oobaltite. 



Isometric. Crystals like those of pyrite, but silver-white 

 in color with a tinge of red, or inclined to steel-gray. Streak 

 grayish black. Brittle. H. = 5 -5. G. = 6 -63. 



Composition. Co S 2 + Co As 2 = Co AsS = Arsenic 45*2, sul- 

 phur 19*3, cobalt 35-5 = 100, but often with much iron 

 and occasionally a little copper. Unaltered in the closed 



