Rhodochrosite is a manganese carbonate mineral. In its rarer and purer form it has a rose-red color, but the presence of impurities may vary its color from shades of pink to pale brown.

It streaks white and its hardness on Moh’s scale varies between 3.5 and 4. It crystallizes in the trigonal system. It varies from transparent to translucent. It is often confused with the manganese silicate rhodonite but is softer.

Calcium, Magnesium and Zinc frequently replace manganese in the crystal 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 seen is pink. The name of the crystal is derived from a Greek word meaning rose-colored.

Its main use is as an ore of manganese-which is a key component of low-cost stainless steel and certain alloys of aluminium. Quality specimens are used in decorative carving and in jewelry. Since it is soft and has a perfect cleavage, it is difficult to facet the crystal.

Rhodochrosite is state mineral of Colorado since 2002. Large red crystals are found only in a few places on the earth and fine specimens have been found in Alma, Colorado. The Alma King is the largest known rhodochrosite crystal. It was found in the Sweet Home Mine near Alma, Colorado. It is on display in the Denver Museum of Nature and Science.