Sphalerite with Calcite

This specimen slays me. Jet black twinned Sphalerite selectively coated with Calcites (LW reactive). The composition of this piece is near perfection as the bottom crystals exhibit an open (incomplete?) structure with dozens of growth features. A must for the collector of Sphalerites or Kosovo specimens. Ex Mike Wortham

Locality: Stari Trg Mine, Trepca, Kosovo

Composition: zinc sulfide