Nickeline - NiAs

Habit: Crystals are rare, nickeline usually massive pale copper-red, tarnishes gray or black. Metallic Luster, opaque

Environment: Occurs in ore deposits with other nickel and arsenic minerals and in veins containing silver and copper.

Etymology: From the nickel component in its formula and also from the German kupernickel, "devil's copper" as the mineral was believed to contain copper but yielded none