Mineral - Skutterudite
Skutterudite
Chemical Properties
Mineral Class
Sulfides and sulfosalts
Toxicity
middle
Formula
CoAs₃
Unit Cell
a=8.20 Z=8
Physical Properties
Hardness
5.5 - 6
Streak
black
Density
Very Heavy (>6)
Cleavage
Distinct after {001} and {111}
Fracture
conchoidal,
uneven
Tenacity
Brittle
Optical Properties
Color
graysilver
Birefringence
Luster
Metallic
Transparency
opaque
Pleochroism
Geomineralogical Properties
Crystal System
isometric
Point Group
diploidal - 2/m 3
Space Group
Im 3 (204)
Habit
dendritic, dodecahedron, massive, Octahedron, Cube
Formation
(1) Primary hydrothermal in medium- to high-temperature veins.
(2) Metamorphic-metasomatic through mobilization and recrystallization in arsenic-bearing sulfide deposits under granulite- to amphibolite-facies conditions.
Paragenesis
Twinning
Rotational twins after {112} - Sixlings
Rarity
Rarely
Synonyms
Skutterudite
Composition
Elements
Mass
Co
19.70
Fe
2.80
As
76.41
S
1.03
Norway (Palache et al. 1952)
Groups and Members
Perovskite-Group
Skutterudite-Subgroup