Description
Well formed sphalerite cluster with pyrite after pyrrhotite, from Trepca Mine Complex, Mitrovica, Kosovo.
This spectacular specimen has cubic pyrite replacing the original platy or sheet-like pyrrhotite crystals with terminated black sphalerite crystals.
Size: 68 x 45 x 32 mm. 128 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.