Mineral - Galena
Galena
Chemical Properties
Mineral Class
Sulfides and sulfosalts
Toxicity
middle
Formula
PbS
Unit Cell
a=5.93 Z=4
Physical Properties
Hardness
2.5
Streak
blackgraygray black
Density
Very Heavy (>6)
Cleavage
Perfect after {100}
Fracture
conchoidal
Tenacity
Brittle
Optical Properties
Color
blackgray
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, Octahedron, Cube
Formation
In hydrothermal ore deposits
Paragenesis
Twinning
Contact twins and penetration twins after {111}, often referred to as pseudohexagonal contact twins after the spinel law
Rarity
Common
Synonyms
Galena, Bleiglanz
Composition
Elements
Mass
Pb
86.50
Cu
0.07
S
13.31
England (Palache et al. 1952)
Groups and Members
Galena-Group