Pseudomorph Goethite After Marcasite | Prophecy Stone | 51.7 gr | Farafra Oasis, Egypt | SO24 autopostr_pinterest_71214 Name: Gypsum var

Name: Gypsum var

This superb specimen is from the gem pegmatites of Nooristan

5 Ounces (including box)  Origin: Mined in Emmons Quarry

Although dinosaurs are the most well-known fossil life forms

Pseudomorph Goethite After Marcasite | Prophecy Stone | 51.7 gr | Farafra Oasis, Egypt | SO24 autopostr_pinterest_71214 Name: Gypsum varPseudomorphs 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