Rhodochrosite is an interesting rose-colored gemstone that was only introduced to the market around 1940. Though it is not particularly hard -- rating only 4 on the Mohs scale -- it has become popular as a decorative material due to its attractive soft color and its intriguing variegated markings.
Like rhodolite garnet, rhodochrosite draws its name from the Greek for 'rose' (rhodochrosite means 'rose colored'). By chemical composition rhodochrosite is a manganese carbonate. It is related to the mineral calcite, but where calcite has calcium, rhodochrosite has manganese. Transparent red crystals are rare; rhodochrosite is usually found in an aggregate form with alternating light and dark stripes in zigzag bands, somewhat similar in that respect to malachite or agate. The most common colors are light red and pink and it displays a vitreous luster when polished.
Rhodochrosite was first described in 1813 based on a sample from Romania. It most commonly forms in hydrothermal veins associated with silver, copper, and lead sulfides. It was named the state mineral in mineral-rich Colorado in 2002, since some rare large red crystals have been found at the famous Sweet Home Mine near Alma, Colorado. From the gemological perspective, rhodochrosite has a density of 3.45-3.70 and a refractive index of 1.600-1.820.
Rhodochrosite is almost always cut as cabochons or beads or carved. Rare transparent crystals may be faceted, but they are usually heavily included. Fine, blood-red rhodochrosite mineral specimens are highly desired by collectors, and sometimes command extraordinary prices in the market.
Significant deposits are found in Argentina from localities along the eastern side of the mountains in the west of the country, especially in the province of Catamarca. Other deposits are found in Chile, Mexico, Peru, South Africa, Namibia, Russia, Canada and the USA (Colorado and Montana).
- First Published: July-08-2008
- Last Updated: October-06-2010
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