22196 - Calcite Geode with Gypsum Crystal 680 g in Natural Matrix Sphenopteris Spectacular example of tooth belonging

Spectacular example of tooth belonging to an individual of Spinosaurus

Precious tooth of Eremiasaurus heterodontus (Mosasaur) from the phosphate deposits of the Ouled Abdoun Basin (Morocco)

Petrography: (A

They come from the famous sites of the Judith River Formation in Montana (Campanian stage

Unique plate handmade in the south of morocco

22196 - Calcite Geode with Gypsum Crystal 680 g in Natural Matrix Sphenopteris Spectacular example of tooth belongingSIZE: 142. 6 mm 5. 61 in WEIGHT: 680 g Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (CaCO3). The Mohs scale of mineral hardness, based on scratch hardness comparison, defines value 3 as "calcite". Other polymorphs of calcium carbonate are the minerals aragonite and vaterite. Aragonite will change to calcite over timescales of days or less at temperatures exceeding 300 C and vaterite is even less stable. Gypsum is a