Rhodochrosite

Description

Colorado’s State Mineral, Rhodochrosite has a hardness of 3½ – 4 and a specific gravity of 3.7. It was named in 1813 by Johann Friedrich Ludwig Hausmann from the Greek ρόδο, “rose”, and χρώς, “coloring”, referring to its color.

It commonly occurs as a primary gangue mineral in moderate- to low-temperature hydrothermal veins, also in high-temperature metasomatic deposits and sedimentary manganese deposits or as a late stage hydrothermal mineral in pegmatites, especially lithiophilite-bearing ones, and it can also be formed as a biomineral by some fungi during oxidation.

The Sweet Home Mine opened in 1873 as a Silver mine and quickly became famous as Colorado’s top Rhodochrosite mine, with the “Alma King” crystal displayed at the Denver Museum of Nature and Science, and “Alma Rose” crystal displayed at the Rice Northwest Museum of Rocks and Minerals in Oregon. Specimens of Sweet Home Mine Rhodochrosite are also displayed at the geology museum at the Colorado School of Mines, in the Royal Ontario Museum, the Houston Museum of Natural Science, and in many other museums and hundreds of private collections.

You can find additional and much larger and more stunning specimens at the CollectorsEdge website, where the Sweet Home miners have their shop, as well as a bunch of additional information, from where this passage was taken describing its geology, “Hydrothermal alteration directly related to vein mineralization is pronounced in certain rock types at the Sweet Home mine. This alteration type consists of varying amounts of hydrothermal muscovite, pyrite, quartz and fluorite. In places quartz and pyrite may dominate along with fine-grained sericite. In such cases, the alteration type is best termed phyllic alteration. The more typical alteration type, however, consists of a mixture of coarse-grained, snow-white muscovite, fine-grained fluorite, pyrite, and quartz. This alteration type commonly occurs as replacements of wall rock adjacent to early stage quartz-pyrite-fluorite +- huebnerite +- sphalerite veins and represents a greisen type of alteration.”

It’s found in thousands of locations around the world, but rarely can you find more incredible specimens than those found in Colorado, and most notably, from the Sweet Home Mine! Colorado’s ~182 other localities have also produced some of the most stunning specimens to date, and some have sold for tens of thousands of dollars, so be sure keep an eye out for a cool rose-colored mineral like this on your next hike!