Pyrite ps. After Pyrrhotite with epitaxial Arsenopyrite

Item Description

This remarkable pseudomorph is one of the better examples I have seen from the locality, for which they are very rare, of pyrite that has completely replaced original pyrrhotite crystals. One never sees pyrrhotite today - at least I have not, so I presume it was all altered in the geologic past. This is an aesthetic small cab with crystals to 2 inches (5 cm) showing the sharp hexagonal form of pyrrhotite. Yet, they are now made of pyrite. Atop the pyrite run thin crystals of arsenopyrite in an exquisite pattern, semeingly epitaxial (related to the axis of the underlaying crystal) upon the surface of the pyrite. Some small, sharp arsenopyrite crystals stick up, too, forming sharp horizons of spikes around the former pyrrhotites. This is an outstanding specimen for several reasons, valued $750 or more. but it is notoriously hard to photograph and so will be MUCH BETTER IN PERSON