Arrangement of Minerals, 367 



Genus V. Copper-Pvrites. 

 Tessular. Pyramidal. Colour brass-yellow, copper-red. Hard- 

 ness = 3.0 — 4.0. Sp. gr. 4.1— 5.1. 



1, Octahedral Copper-Pyrites {Variegated or Purple Copper), 2. 

 Pyramidal Copper-Pyrites, {Yellow Copper-Pyrites). 



Order IV. GLANCE. 

 Metallic. Colour grey, black, brown. Hardness = 1.0 

 — 4.0. Sp.gr. =4.2 — 8.5. 



Genus I. Copper-Glance (Dystom Glance, Mohs), 

 Tessular. Rhombohedral. Prismatic, and Hemiprismatic Colour 

 steel-grey, sometimes inclining to yellow, blackish lead-grey, iron- 

 black. Cleavage imperfect, not axotomous. Brittle. Hardness 

 = 2.5 — 4.0. Sp. gr. = 4.3 — 5.8. 



1. Hexahedral Copper-Glance {Stanniferous Copper-Glance, Bell- 

 Metal Ore. Zinnkies, W.) 2. Tetrahedral Copper-Glance 

 {Grey Copper. Fahlerz,W. Schwarzerz,W, Cuivre gris, H.) 

 3. Dodecahedral Copper-Glance {Tennantite). 4. Prismatoidal 

 Copper-Glance {Antimonial Copper- Glance). 5. Diprismatic 

 Copper-Glance {Bournonite. Schwarz Spiesglaserz, W. Plomb 

 Sulphure Antimonifere, H. Endellione. Triple Sulphuret).* 



Genus H. Vitreous Copper. 

 Prismatic. Cleavage imperfect, not axotomous. Colour blackish 

 lead-grey. Streak more or less shining. Very sectile. Hardness 

 = 2.5 — 3.0. Sp. gr 5.5 — 6.3. 



1. Prismatic Vitreous Copper. {Kvpferglas, W.) Jl. Isometric Vi- 

 treous Copper. {Silberkupferglanz, Hausmann). 



Genus HI. Silver-Glance. 

 Tessular. Colour blackish lead-grey. Malleable. Hardness = 2.0 

 ^ 2.5. Sp. gr. = 6.9 — 7.2. 



1. Hexahedral Silver Glance. {Argent Sulphure , H.) 

 Genus IV. Lead-Glance. 

 Tessular. Colour pure lead-grey. Sectile. Hardness = 2.5. Sp. 

 gr. =6.8 — 7.6. 



1. Hexahedral Lead-Glance. {Plomb Sulphure, H.) 2. Octahedral 

 Lead-Glance. {Steinmannite, Zippe.) 



Genus V. Eutomous Glance.j 

 Pyramidal. Rhombohedral. Prismatic. Cleavage monotomous, very 



* Zinkenite and Plagionite are placed in this genus by Mohs. 



f Euionwus (from w, easily f and rt^vw. to ckave), cleavage easily effected. 



