This Specimen has been sold.
3.8" Fantastic Sphalerite Cluster With - Bolognesi, Peru
This is a unique specimen that contains an association of sphalerite and two other minerals. The sphalerite is encrusted in what appears to be barite or calcite, and there are translucent yellow crystals scattered throughout the specimen. While sphalerite crystals can be translucent and yellow, based on the opaque sphalerite that the mineral formed in association with, it's unlikely to be sphalerite. It comes from the Huanzala Mine in Peru and the entire specimen measures 3.8" 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.