Calcite with Pyrite

Item Description

Pyrite (usually considered to be chalcopyrite or marcasite) with lustrous, translucent, gray calcite scalenohedrons are a Brushy Creek Mine classic. This is a very fine and well-composed specimen of sparkly pyrite crystals preferentially coating the recessed areas of the calcites. What actually happened is that the original crystals were covered with chalcopyrite, and then the calcite began growing again, enveloping the original crystals in some areas and leaving the chalcopyrite exposed in others, - so these are phantoms. You can see the surface of the original crystals inside the later, transparent overgrowths. This is a showy and pristine piece. RARE TODAY! We just consulted with a sulfide ore expert, who confirmed these as pyrite or possibly pyrite pseudos after chalcopyrite.