Chemical Properties
Arsenopyrite, FeAsS, crystals to 4 mm. Hidalgo del Parral, Chihuahua, Mexico.
Physical properties
Habit: faces striated, euhedral crystals, prismatic.
Color: tin white or light steel gray.
Luster: metallic.
Diaphaneity: opaque.
Streak: black.
Cleavage: {110} distinct.
Twinning: {100}, {101}, {012}.
Fracture: uneven, brittle. Electrical resistivity 20 to
300 μΩ.cm.
