Mineral - Berzelianite
Berzelianite
Chemical Properties
Mineral Class
Sulfides and sulfosalts
Toxicity
middle
Formula
Cu₂Se
Unit Cell
a=5.69 Z=4
Physical Properties
Hardness
2
Streak
blackgraygray black
Density
Very Heavy (>6)
Cleavage
Fracture
uneven
Tenacity
Inelastic-flexible
Optical Properties
Color
graysilver
Birefringence
Luster
Metallic
Transparency
opaque
Pleochroism
Geomineralogical Properties
Crystal System
isometric
Point Group
hexoctahedral - 4/m 3 2/m
Space Group
Fm 3 m (225)
Habit
dendritic, massive
Formation
In hydrothermal ore deposits
Paragenesis
Twinning
Rarity
Rarely
Synonyms
Berzelianite
Composition
Elements
Mass
Cu
57.21
Ag
3.51
Se
39.22
Sweden (Palache et al. 1952)
Groups and Members
Berzelianite-Umangite-Group