09169 - Top Beautiful 4.25 Inch Pink Cobaltoan Calcite Crystals on Matrix - Bou Azzer Mine (South Morocco) Dolomite • Desmoinesian of United States

• Desmoinesian of United States (1: Missouri)

Euphemerites gigas

center of the second image are barite

two carinae and enamel ornamented by minute ridges

Unidentified species

09169 - Top Beautiful 4.25 Inch Pink Cobaltoan Calcite Crystals on Matrix - Bou Azzer Mine (South Morocco) Dolomite • Desmoinesian of United StatesCalcite 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". The Cobaltoan calcite is a variety of calcite containing Co2+ replacing Ca, that's the reason for its pretty pink color.