Mineral - Sperrylite
Sperrylite
Chemical Properties
Mineral Class
Sulfides and sulfosalts
Toxicity
low
Formula
PtAs₂
Unit Cell
a=5.97 Z=4
Physical Properties
Hardness
6 - 7
Streak
black
Density
Very Heavy (>6)
Cleavage
Indistinct after {001}
Fracture
conchoidal
Tenacity
Brittle
Optical Properties
Color
whitesilver
Birefringence
Luster
Metallic
Transparency
opaque
Pleochroism
Geomineralogical Properties
Crystal System
isometric
Point Group
diploidal - 2/m 3
Space Group
Pa 3 (205)
Habit
dodecahedron
Formation
(1) Primarily magmatic, formed by fractional crystallization or liquid segregation from sulfide melts of mafic to ultramafic intrusions.
(2) Hydrothermal, formed by precipitation from fluoride- or chloride-rich fluid phases in contact metasomatites or hydrothermal veins.
Paragenesis
Twinning
Rarity
Very rare
Synonyms
Sperrylite
Composition
Elements
Mass
Pt
56.80
Sb
0.08
As
42.80
Canada (Palache et al. 1952)
Groups and Members
Pyrite-Group