Frac 



PHYSIOGRAPHY. 



Bismuth-Blende Bismuthine. 



57 



Fracture imperfectly conchoidal or uneven. 



Lustre resinous. Color dark hair-brown, yellowish-grey 

 and straw-yellow. Streak yellowish-grey. Translucent 

 DF opake. 



Rather brittle. Hardness = 3-5 ... 4-0. Sp. gr. = 

 5-9... 6-0. 



1. It decrepitates briskly before the blow-pipe, emits an arsenical odor, 

 and is finally converted into a glass, which effervesces with borax. 



2. Analysis. 



By HUNEFELD. 



Carbonate of bismuth ..... 58-8 



Arsenic acid 2-2 



Silica 23-8 



Arsenic, cobalt, copper and iron . . . 5-ft 



Gangue 9-1 



3. It occurs with Quartz at Schneeberg in Saxony. 



BISMUTHIC COBALT-ORE. 



The description of this species, as put forth by KERSTEN, is 

 too defective to enable us to decide whether it is entitled to rank 

 as a distinct species. It is described as massive, having a lead or 

 steel-grey color, a feebly metallic lustre and a sp. gr. from 6-0 . . . 

 7-8. It is believed to consist of arsenic, cobalt and bismuth. It 

 occurs with other ores of cobalt at Schneeberg in Saxony. 



BISMUTHINE. Prismatic Polypoione-Glance. 



Primary form. Right rhombic prism. M on M= near- 

 ly 91. 



Secondary form. 



The lines parallel to the plane/, rep- 

 resent the striae constantly observed on 

 the crystals, but which in reality are a 

 series of planes. 



