CLASSIFICATION OF MINERALS. 



757 



CLASS, — ARSENIDES, ANTIMONIDF.S, AND lUSMUTHIDES. 



Arsenic, antimony, and bisnnitli are analogons in tlieir properties 

 and unite with other elements to form arsenides, antimouides, and bis- 

 muthides. Arsenic and antimony, and to a certain extent bismuth, are 

 essentially isomorphous and may replace one another in varying 

 amounts. With the arsenides, antimouides, and bismuthides are 

 included the sulpharsenides, sulphantimonides, and sulphbismuthides — 

 compounds in which tlie negative i)art is taken by arsenic, antimony, 

 or bismuth with sulphur. 



Group 1. 



Hexagonal. 

 Hexagonal. 

 Hexagonal. 



Orthorbombic. 



Ortborhorabic. 



Isometric. 



Isometric. 



OrtliorboMibic. 



Isometric. 



Lsometric. 

 Isometric. 



Ortborhombic. 



(?) 



Ortborbombic. 



(?) 



(?) 



