Mineral - Stibnite
Stibnite
Chemical Properties
Mineral Class
Sulfides and sulfosalts
Toxicity
low
Formula
Sb₂S₃
Unit Cell
a=11.23 b=11.31 c=3.84 Z=4
Physical Properties
Hardness
2 - 2.5
Streak
gray
Density
Heavy (3,5-6)
Cleavage
Perfect after {010}, imperfect after {100} and {110}
Fracture
splintery
Tenacity
Elastic-flexible
Optical Properties
Color
blackgray
Birefringence
Luster
Metallic
Transparency
opaque
Pleochroism
Geomineralogical Properties
Crystal System
orthorhombic
Point Group
orthorhombic-dipyramidal - 2/m 2/m 2/m
Space Group
Pnma (62)
Habit
lath-shaped, acicular, prismatic, radial, prismatic, tabular
Formation
(1) Hydrothermal, formed by precipitation from low-temperature (epithermal) aqueous solutions in quartz veins
(2) Secondary, as an oxidation product of primary antimony minerals in the oxidation zone of ore deposits
Paragenesis
Twinning
Rarity
Rather rare
Synonyms
Stibnite
Composition
Elements
Mass
Sb
71.45
S
28.42
Germany (Palache et al. 1952)
Groups and Members
Stibnite-Group