Pseudomorph Goethite After Marcasite | Prophecy Stone | 72 gr | Farafra Oasis, Egypt | SO24 Perky Box The crater rim is formed

The crater rim is formed by steeply inclined and intensely brecciated Upper Jurassic limestone blocks that also contain numerous shattered chert nodules

pyritized molds of gastropods

Color: Rich Purple

33 KG / 2 lbs 14 oz

ranging from colorless to white

Pseudomorph Goethite After Marcasite | Prophecy Stone | 72 gr | Farafra Oasis, Egypt | SO24 Perky Box The crater rim is formedPseudomorphs 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