1.8" Sphalerite "Flower" and Marcasite Association - Missouri
This beautiful specimen contains an association of a deep red sphalerite "flower" crystal cluster and small amounts of marcasite druze. It comes from the Washington County Aggregates Quarry in the Potosi Barite District of Missouri.
Sphalerite is a part of the sulfides group and typically exhibits a grey/black appearance due to high concentrations of impurities. When sphalerite is in it's purest state, the chemical composition is ZnS, and can display a gemmy transparent light tan/yellow color. This is one of the few minerals that can form crystals ranging anywhere between gemmy and transparent to opaque and metallic-like. Opaque or cloudy sphalerite tends to be most abundant, due to the ease of iron replacing zinc in the process of formation.