Arrangement of Minerals, 365 



Genus I. Arsenic. 

 Rhombohedral. Colour tin-white. Hardness = 3.5. Sp. gr. == 

 5.7 — 5.8. 



1. Rhombohedral Arsenic. 



Genus II. Tellurium. 

 Tessular, rhombohedral. Colour tin-white. Not ductile. Hard- 

 ness = 2.0 — 3.5. Sp. gr. = 6.1 — 8.6. 



1. Rhombohedral Tellurium {Native Tellurium). 2. Uncleavable 

 Tellurium {Argentiferous Tellurium). 3. Hexahedral Tellurium 

 {Plumbiferous Tellurium). 



Genus III. Antimony. 

 Rhombohedral. Prismatic. Colour white, but not inclining to red. 

 Not ductile. Hardness =3.0—3.5. Sp. gr. = 6.5 — 10.0 



1. Rbombohedral Antimony, or Native Antimony. 2. Prismatic 

 Antimony, or Antimonial Silver. 



Genus IV. Bismuth. 

 Tessular. Cleavage perfect. Colour silver-white, inclining'to red. 

 Not ductile. Hardness = 2.0 -— 2.5. Sp. gr. = 9-6, 9.8. 

 1. .Octahedral Bismuth. 



Genus V. Mercury. 

 Tessular ; liquid ; not cleavable. Colour white. Not malleable. 

 Hardness = 0.0—3.5. Sp. gr. = 10.5 — 15.0. 



1. Dodecahedral Mercury, or Natural Amalgam. 2. Fluid Mercury. 

 Genus VI. Silver. 

 Tessular. Uncleavable. Colour silver-white. Ductile. Hard- 

 ness = 2.5 — 3.0. Sp. gr. = 1 — 11 .0. 

 1. Hexahedral Silver. 



Genus VII. Gold. 

 Tessular. Colour gold-yellow. Hardness = 2.5 — 3.0. Sp. gr. 

 12.0 — 20.0. 



1. Hexahedral Gold. 



Genus VIII. Iridium. 

 Rhombohedral. Easily cleavable. Colour light steel-grey. Duc- 

 tile. Hardness = 7.0. Sp. gr. = 19.0 — 20.0. 

 1 . Rhombohedral Iridium. 



Genus IX. Palladium. 

 Tessular. Colour steel-grey. Ductile. Harduess = 4.6 — 5.0, 

 Sp.gr. =11.5—12.5. 



1. Hexahedral Palladium. 

 VOL. XXXI. NO. LXII.— -OCTOBER 1841. A a 



