Mineral - Arsenopyrite
Arsenopyrite
Chemical Properties
Mineral Class
Sulfides and sulfosalts
Toxicity
low
Formula
FeAsS
Unit Cell
a=5.74 b=5.68 c=5.79 β=112° Z=4
Physical Properties
Hardness
5.5 - 6
Streak
black
Density
Very Heavy (>6)
Cleavage
Distinct after {001}
Fracture
uneven
Tenacity
Brittle
Optical Properties
Color
graysilverbronze
Birefringence
Luster
Metallic
Transparency
opaque
Pleochroism
Geomineralogical Properties
Crystal System
monoclinic
Point Group
monoclinic-prismatic - 2/m
Space Group
P2 1 /c (14)
Habit
blocky, dipyramidal, wedge-shaped, prismatic, tabular
Formation
Primarily in hydrothermal ore deposits
In magmatic pegmatites
Near contact metamorphic rocks, through metasomatism
Paragenesis
Twinning
Penetration twins after {101}
Penetration twins after {201}
Rotation twins after {201} (snowflake-shaped)
Rotation twins after {110} (star-shaped)
Rarity
Common
Synonyms
Arsenopyrite
Composition
Elements
Mass
Fe
34.53
Co
0.09
Bi
0.79
As
44.34
S
20.22
Canada (Palache et al. 1952)
Groups and Members
Arsenopyrite-Group
Name and first discovery : Named after its chemical composition, an arsenic-containing pyrite.
Chemistry :
Synonyms :
Varieties : Cobalt-Arsenopyrite, Danaite
Abbreviation : Apy
literature
Palache, C., Berman, H., & Frondel, C. (1952). Dana's system of mineralogy. Geologiska Föreningen i Stockholm Förhandlingar , 74 (2), 218-219.