Chalcopyrite on Sphalerite with Fluorite

A very different looking Illinois specimen with modified cubic surficially deep purple fluorites to 2.5cm on which large sphalerite clusters formed on either side. The sphalerites were then heavily sprinkled with chalcopyrites, giving a golden dusted appearance. The fluorites have yellow cores and are transluscent with back light.

Locality: Rosiclare Level, Annabel Lee Mine, Harris Creek District, Hardin County Illinois

Composition: calcium fluoride and zinc sulfide