Description
The mineral rhodochrosite, or manganese spar, is a manganese carbonate with the chemical formula Mn2+CO3–. Yellowish-gray, brown, but usually pinkish-red, rhodochrosite has a vitreous luster and a white streaky color. Its crystal system is trigonal, and its cleavage is perfect along the crystal plane [1011]. Its average density is 3.69, and its hardness is 3. Rhodochrosite is not radioactive. It usually occurs as crystals, granular, or massive, and occasionally as spherical lumps with internal concentric colored bands. The mineral is a source of manganese and is used as such to harden steel. The name rhodochrosite is derived from the Greek rhodon (“pink or red-colored”) and chroma (“color”). Rhodochrosite occurs in manganese-bearing carbonate-rich rocks that become oxidized. The mineral is also found in hydrothermal veins, along with ores of copper, silver, and lead, and in some metamorphic rocks of sedimentary origin. The type locality is Cavnic (Kapnik), Maramures, Romania. It is also found in Alma, Colorado, United States.
