RHODOCROSITE, A RED/PINK MINERAL

 Rhodocrosite

This relatively rare mineral consists of manganese carbonate (MnCO3) and is a gemstone prized for its red to pink color with some white bands. It rarely forms large crystals. It is a rather soft mineral, however. On the Mohs Hardness Scale (1 to 10) for minerals, it scores at 3.5 to 4; thus it is rather delicate for jewelry (use care).

Figures 1 and 2, both from the Smithsonian Institution (open access).

 

Rhodocrosite  rarely forms large crystals. It occurs in the trigonal crystal system and commonly occurs in rhomboid-shaped crystals. Thus, it has typical calcite cleavage (i.e., rhombohedral). It forms often as a hydrothermal-vein mineral at low-to-moderate temperatures (e.g. in certain ore deposits).  It can co-occur with silver, lead, zinc, and copper sulphide ores. 

Rhodocrosite is mined in Montana (Butte area), Colorado, Peru, Argentina [= the national stone], Romania, and South Africa, and this mineral is source of manganese. 

This reddish-pink mineral is used in jewelry, and is also sought after by mineral collectors.

References

Berry, L.G. and B. Mason. 1959. Mineralogy: Concepts, Descriptions, Determinations. W.H. Freeman and Company, San Francisco. 630 pp.

Sorrell, C.A. 1973. Rocks and Minerals. Golden Guide Book. Guide to field identification rocks and minerals. New York. 280 pp.