Composition: AsSbS3
Crystal System: Monoclinic
Color: Red, Orange-red
Type Locality: Getchell Mine, Potosi District, Humboldt County, Nevada
Getchellite is a rare mineral found in low-temperature environments. Getchellite was first discovered at the Getchell Mine, an underground/open pit gold mine, in 1965. It occurs there as red, platy crystals in ore associated with other arsenic and antimony sulfide minerals such as orpiment, realgar, pararealgar, and stibnite. The only other major occurrence of getchellite is the antimony-mercury mine at Khaidarkan, Kyrgyzstan, where it occurs as large cleavages in calcite. Minor occurrences are at the Twin Creeks Mine near Getchell, at Gal-Khaya, Russia, and at deposits in Azerbaijan and Iran.
The Getchell deposit was discovered in 1934 by two prospectors grubstaked by Noble H. Getchell of Battle Mountain. The prospectors had samples from the area fire assayed, because no gold could be seen in the ore. It was one of the first deposits of “invisible” gold to be found in Nevada, well before the 1961 discovery of the disseminated Carlin deposit. In fact, Getchell is a Carlin-type deposit. With backing from notables such as George Wingfield, Eleanor Roosevelt, and Newmont Mining, Getchell set out to develop the property. The operation was troubled immediately by the high arsenic content of the ore, called 'refractory ore' today. Despite this, the Getchell Mine was the leading gold producer in Nevada from 1939-1941. The mine was shut down for several periods during the 1970s and 1980s, but after renewed interest it was reactivated and remains in operation today. From Minerals of Nevada, by Castor and Ferdock, 2003.
Getchellite in orpiment, Getchell Mine, Nevada. |
 Close-up of getchellite zone, showing pearly cleavage surfaces. Getchellite zone is about 1 centimeter wide. Photo by Ben Schumer |
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