Mineral - Enargite
Enargite
Chemical Properties
Mineral Class
Sulfides and sulfosalts
Toxicity
none
Formula
Cu₂CuAsS₄
Unit Cell
a=7.41 b=6.44 c=6.15 Z=2
Physical Properties
Hardness
3
Streak
blackgraygray black
Density
Heavy (3,5-6)
Cleavage
Perfect after {110}, imperfect after {100} and {010}
Fracture
uneven
Tenacity
Brittle
Optical Properties
Color
blackgray
Birefringence
Luster
Metallic
Transparency
opaque
Pleochroism
Geomineralogical Properties
Crystal System
orthorhombic
Point Group
orthorhombic-pyramidal - mm2
Space Group
Pmn2 1 (31)
Habit
prismatic, tabular
Formation
hydrothermal
Paragenesis
Twinning
Star-shaped interpenetration twins after {320}
Rarity
Rather rare
Synonyms
Enargite
Composition
Elements
Mass
Cu
47.96
Fe
1.22
Zn
0.57
As
18.16
S
32.21
Chile (Palache et al. 1952)