Galena

Galena has metallic to lead-gray, cube-shaped crystals that break into cubic, right-angled fragments. It is an ore—a mineral of economic value—that was once mined in southeastern Kansas for its lead content. The Tri-State mining district, which includes the far southeastern corner of the state, was formerly one of the most important lead- and zinc-producing areas in the world.

Chemical compound: lead sulfide
Chemical formula: PbS (Pb = lead, S = sulfur)
Color: lead gray
Streak: gray-black
Luster: metallic
Hardness: 2.5
Specific gravity: 7.5
Amount of transparency: opaque