Gorgeous Rhodochrosite Crystals From South Africa
Gorgeous Rhodochrosite Crystals From South Africa. Photo Credit: László Tóth

Rhodochrosite | ‪#‎Geology


Formula: MnCO3
System: Trigonal
Colour: Pink, rose, red, ...
Lustre: Vitreous, Pearly
Hardness: 3½ - 4 Tenacity: Brittle

From N'Chwaning I mine, South Africa

Rhodochrosite is a manganese carbonate mineral with chemical composition MnCO₃. In its pure form, it is typically a rose-red color, but can also be shades of pink to pale brown. It streaks white, and its Mohs hardness varies between 3.5 and 4.5. Its specific gravity is between 3.45 and 3.6.

Rhodochrosite forms a complete solid solution series with iron carbonate (siderite). Calcium, (as well as magnesium and zinc, to a limited extent) frequently substitutes for manganese in the structure, leading to lighter shades of red and pink, depending on the degree of substitution. It is for this reason that the most common color encountered is pink.


 
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