BISMUTH. 419 



ORDER V. BISMUTH. 



1. Native Bismuth. 

 NATIVE BISMUTH. 



Bismuth Natif. Hauy, — Native Bismuth. Cleaveland, PkiMps,' Thomson and Shepard. — Bismuth. Beadant. — 

 Octahedral Bismuth. Jameson. — Octaedrisches Wismuth. Mohs. 



^* 501- Descrition. Colour silver-white with a tint of red ; liable to tar- 



nish. It occurs regularly crystallized ; also massive, disseminated, 

 and in leaves having a feathery surface. Primary form the regular 

 octahedron, Fig. 501. Cleavage parallel with the planes of the pri- 

 mary. Lustre metallic. Soft. Sectile. Opaque. Hardness from 2 . 

 to 2.5. Specific gravity 9.74. Very fusible by the blowpipe, giving 

 a yellow oxide, which is deposited on the charcoal. Soluble in nitric 

 acidj with the disengagement of nitrous acid vapours. When the 

 solution is diluted, a white curdy precipitate falls. In a glass tube 

 it gives almost no smoke, and the metal becomes covered with a fused oxide of a dark brown 

 colour, which on cooling becomes yellow. By this reaction, it is distinguished from native 

 antimony and tellurium ( Von Kohell). 



Composition. This substance, when found in nature, is often mixed with small quantities 

 of sulphur and arsenic. 



Geological Situation. It occurs in veins in primitive rocks, as gneiss, mica slate, etc. 



LOCALITIES. 



Dr. Emmons states that he has found a single specimen of native bismuth in Essex county.* 

 The only other known locality in the United States, is Monroe, Connecticut, where it is found 

 in a bed of quartz with galena, zinc blende, wolfram, etc. 



* Maraud of Mineralogy and Geology. 



