CUPREOUS BISMUTH. 91 



Lustre vitreous. Colour brownish-black. Streak 



dark leek-green. Opake. 

 Thin laminae are elastic. Hardness = 2*5 (nearly). 



Sp. Gr. = 3-348, STEIXMANN. 



Before the blowpipe it froths a little without melting : 

 with borax it yields a black opake and hard bead. Reduced 

 to powder, it gelatinises in concentrated muriatic acid. It 

 consists, according to STEINMANN, of 



Silica 22-452. 



Oxide of Iron 58-853. 



Oxide of Manganese 2-885. 



Magnesia 5-078. 



Water 10-700. 



It occurs at Przibram in Bohemia, in veins containing 

 silver-ores, along with prismatic Iron-ore, brachytypous 

 Parachrose-baryte, prismatic Iron-pyrites, and rhombohe- 

 dral Lime-haloide. It has also been found at Wheal Maud* 

 lin in Cornwall. 



CUPEEOUS BISMUTH. 

 GLANCE ? 



Cupreous Bismuth or Cupriferous Sulphuretted Bismuth. 

 JAM. Syst. Vol. III. p. 386. Cupriferous Sulphuret 

 of Bismuth. PHILL. p. 274. 



Massive: composition columnar, impalpable. Frac- 

 ture uneven. 



L'ustre metallic. Colour pale lead- grey, passing 

 into steel-grey and tin-white ; subject to tarnish. 

 Streak black. Opake. 



Sectile. Soft. 



It is partly soluble in nitric acid, leaving the sulphur 

 undissolved. According to KLAPROTH, it consists of 



Bismuth 47-24. 



Copper 34-66. 



Sulphur 12-58. 

 It occurs in the principality of Fiirstenberg, in cobalt- veins, 



