Pyrite After Pyrrhotite with Calcite from Trepca Mine Complex, Kosovo

Pyrite after pyrrhotite, with minor calcite, from Trepca Mine Complex, Mitrovica, Kosovo.

Pyrite after pyrrhotite (psuedomorph). This spectacular specimen has iridescent druzy pyrite replacing the original platy or sheet-like pyrrhotite crystals. The druzy pyrite sparkles brightly in any light.

Size: 50 x 40 x 20 mm. 72 grams.

Pyrite after pyrrhotite pseudomorph is a mineral specimen that shows the replacement of pyrrhotite by pyrite, preserving the original shape and structure of the former. Pyrrhotite is an iron sulfide mineral that often forms hexagonal or pentagonal crystals, sometimes resembling roses. Pyrite is another iron sulfide mineral that has a higher sulfur content and a cubic crystal system. Pyrite is more stable than pyrrhotite and can replace it through a chemical reaction, resulting in a pseudomorph.