Mineral - Tetrahedrite-(Fe)
Tetrahedrite-(Fe)
Chemical Properties
Mineral Class
Sulfides and sulfosalts
Toxicity
low
Formula
Cu₆(Cu₄Fe²⁺₂)Sb₄S₁₂S
Unit Cell
a=10.55 Z=2
Physical Properties
Hardness
3 - 3.5
Streak
blackbrownbrown black
Density
Heavy (3,5-6)
Cleavage
Fracture
conchoidal
Tenacity
Brittle
Optical Properties
Color
blackgray
Birefringence
Luster
Metallic
Transparency
opaque
Pleochroism
Geomineralogical Properties
Crystal System
isometric
Point Group
hextetrahedral - 4 3m
Space Group
I 4 3m (217)
Habit
dodecahedron, massive, Octahedron, pyramidal, Tetrahedron, Triacis octahedron, Cube
Formation
(1) Primarily magmatic within hydrothermal veins, mostly in medium- to low-temperature ranges (mesothermal to epithermal), formed by precipitation from copper- and antimony-rich fluid phases
(2) Less commonly metamorphic, formed by recrystallization or element mobilization in stratiform sulfide deposits under green schist facies conditions.
Paragenesis
Twinning
Drillhead-shaped penetration twins after {111}
Rarity
Rather rare
Synonyms
Tetrahedrite-(Fe)
Composition
Elements
Mass
Cu
45.39
Pb
0.11
Fe
1.32
Sb
28.85
As
0.01
S
24.48
France (Palache et al. 1952)
Groups and Members
Tetrahedrite-Group
Tetrahedrite-Subgroup