Rhodochrosite with Pyrite and Rock Crystal (show pieces of 400-600 grams)

The mineral rhodochrosite or manganese spar is a manganese carbonate with the chemical formula Mn2+CO3--. The yellow-gray, brown, but usually pink-red rhodochrosite has a glass luster and a white stripe color. The crystal system is trigonal and the cleavage is perfect along the crystal plane [1011]. The average density is 3.69 and the hardness is 3. Rhodochrosite is not radioactive. It usually occurs as crystals or in granular or massive form and sometimes as spherical clumps showing concentric, colored bands inside. The mineral is a source of manganese, and as such is used to harden steel. The name of the mineral rhodochrosite is derived from the Greek rhodon ("pink or red-colored") and chroma ("color"). Rhodochrosite occurs in manganese-containing carbonate-rich rocks that become oxidized. The mineral is also found in hydrothermal veins, together with ores of copper, silver and lead, and in some metamorphic rocks of sedimentary origin. The type location is Cavnic (Kapnik), Maramures, Romania. It is also found in Alma, Colorado, United States.