realgar

A soft orange-red arsenic ore, As₂S₂, used in pyrotechnics and tanning and as a pigment.

Arsenic disulphid (As₂S₂), a combination of an equal number of sulphur and arsenic atoms; red sulphuret of arsenic, which is found native in transparent crystals, and also massive.

Arsenic sulphide, a mineral of a brilliant red color; red orpiment. It is also an artificial product.

A mineral, arsenic sulfide (AsS), often associated with orpiment and stibnite in lead, silver and gold ores.

a rare soft orange mineral consisting of arsenic sulphide; an important ore of arsenic