1.9" Translucent Sphalerite Cluster on Calcite - Peru
This is a beautiful formation of translucent sphalerite crystals (resembling sphalerite var. cleiophane) on quartz. It comes from the Huaron Mining District in Peru and the entire specimen measures 1.9" long.
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.