22107 - Top Beautiful Huge 9.57 Inch Calcite Crystals from South Morocco Onchopristis teeth collections Northwest Africa 11273 (NWA 11273)

Northwest Africa 11273 (NWA 11273)

Size (biggest):   1

8 mm  /  1

Some of them have tiny glued and filled fractures

with remarks on African Caudata" Tannina Alloul et al

22107 - Top Beautiful Huge 9.57 Inch Calcite Crystals from South Morocco Onchopristis teeth collections Northwest Africa 11273 (NWA 11273)Huge and sharp crystals of calcite from a new location unpublished in the mountains of the Erich region, Morocco. 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