Physical properties
Habit: prismatic, massive, granular, druse, earthy.
Color: aurora red, orange yellow, or
dark red.
Diaphaneity: translucent to opaque.
Luster: resinous, glassy, adamantine.
Streak: orange red.
Cleavage: [010], [001], and [100].
Twinning: (100).
Fracture: brittle,
sectile.
Chemical: dissolved by HNO3, evolved a garlic odor when calcinated and
gives sublimated As2O3 deposit on cold wall.
Electrical resistivity 1 to 150 mΩ.m.
Occurrence: hydrothermal with orpiment. Marcasite, and stibine. Sedimentary rocks.
Definition
The mineral form of
arsenic(II) sulfide, As
4S
4. It is bright red in
color and used as a pigment, in tanning,
and in pyrotechnics.
