Mineral - Copper
Copper
Chemical Properties
Mineral Class
Elements
Toxicity
none
Formula
Cu
Unit Cell
a=3.62 Z=4
Physical Properties
Hardness
3
Streak
red
Density
Very Heavy (>6)
Cleavage
Fracture
hooked
Tenacity
Inelastic-flexible
Optical Properties
Color
brownbronze
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, coarse
Formation
(1) Magmatic-hydrothermal, through precipitation from copper-rich, low-sulfur fluid solutions in cavities of mafic lavas under reducing conditions.
(2) Sedimentary-diagenetic, through reduction of copper-bearing pore waters in terrestrial red sediments (redbed type) in the presence of organic matter or sulfides.
(3) Secondary, in the cementation zone through reduction of dissolved copper secondary minerals from the oxidation zone (e.g., through tectonic subsidence + rising groundwater).
Paragenesis
Twinning
Contact twins after {111} - Spinel law
Rarity
Very common
Synonyms
Copper, Native Copper
Groups and Members
Copper-Group