Arsenopyrite

Formula: FeAsS

Name: Named in 1847 by Ernst Friedrich Glocker for its composition, a contraction of the antiquated term “arsenical pyrite.” Arsenopyrite was known much before 1847 and arsenopyrite, as a name, may be taken as a simple translation of “arsenkies”.

Color: Silver-white to steel-gray, may have a slight yellow appearance

Lustre: Metallic, Sub-Metallic

Hardness: 5½ – 6

Density: 6.07

Crystal System: Monoclinic

Member of: Arsenopyrite Group