Arsenopyrite

Physical Properties
Chemical formula FeAsS
Class Sulfide
Crystal system Monoclinic
Habit Prismatic, striated crystals
Disseminated
Massive
Granular
Color Silver-white
Hardness 5.5 to 6
Specific gravity 6.1
Cleavage Good (101)
Fracture Uneven
Luster Metallic
Transparency Opaque
Streak Black
Twinning Penetration
Contact
Cyclic
after Perkins, 363

Arsenopyrite in Hand Sample

Arsenopyrite in hand sample

Further Reading

Arsenopyrite at webmineral.com

Arsenopyrite at mindat.org