Sphalerite is zinc sulfide, an ore of zinc. The name comes from the Greek "sphaleros,” meaning treacherous, in reference to how easy it is to mistake the darker varieties for galena, a lead ore.

This sample also has gold colored spots of chalcopyrite.

Depending on the impurities, sphalerite will fluoresce under ultraviolet light. Sphalerite can display triboluminescence of yellow-orange. Typically, specimens cut into end-slabs are ideal for displaying this property.

Triboluminescence is a phenomenon in which light is generated when a material is mechanically pulled apart, ripped, scratched, crushed, or rubbed. The phenomenon is not fully understood but appears in most cases to be caused by the separation and reunification of static electric charges, a property well known about quartz.