Pseudomorph Goethite After Marcasite | Prophecy Stone | 38 gr | Farafra Oasis, Egypt Ring This specimen is certainly one

This specimen is certainly one of a kind

Shape: Oval cut

It is a large specimen and displays beautifully

The total weight of the lot is 20

Pseudomorph Goethite After Marcasite | Prophecy Stone | 38 gr | Farafra Oasis, Egypt Ring This specimen is certainly onePseudomorphs are mineral specimens that have the external shape of one mineral but are composed of another. The pseudomorph goethite after marcasite forms when marcasite is exposed to oxidizing conditions and starts to oxidize and break down. As the marcasite breaks down, goethite replaces it in the crystal structure, preserving the shape of the original marcasite crystal. The resulting specimen appears as a marcasite crystal, but is actually composed