Malachite: March 2013 Mineral of the Month
|Locality Nickname:||Bisbee, Arizona|
|Original Locality 1:||Arizona<|
|Original Locality 2:||Bisbee|
|Min Dat Locality Page:||http://www.mindat.org/loc-3296.html|
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|About the Collection:||http://www.princeton.edu/geosciences/about/mineral-collection|
Winter is drawing to a close in Princeton, so we thought a touch of green would be appropriate. This month’s specimen is a marvelous sample of malachite (copper carbonate, Cu2(CO3)(OH)2.) Malachite has been treasured since ancient times as a pigment and decorative material, for example, the famous vases in St. Petersberg’s Hermitage Museum. Other well-known deposits occur in the Congo, Germany and Australia. This specimen, however, is from the early days of copper mining in the Bisbee, Arizona district, donated by Princeton alum Cleveland Dodge, class of 1879. The stalactitic forms and concentric bands are produced by precipitation from mineralized fluids in the area’s caves, which were once lined with thick masses of malachite and the related blue mineral azurite. The mines have been closed for decades, and therefore existing Bisbee specimens are highly prized.