Getchellite from Khaidarkan, Fergana Valley, Osh Oblast, Kyrgyzstan. Specimen size is 3.6 cm, with a 2.4 cm patch of getchellite on a grey matrix. — Photo: Strickja · Public domain
Getchellite
A rare arsenic-antimony sulfide discovered in 1963 at Nevada's Getchell mine.
Intro adapted from Wikipedia (CC BY-SA).
Getchellite is an IMA-recognized mineral species in the sulfide class, with the chemical formula SbAsS₃.
It crystallizes in the monoclinic crystal system (space group P2_1/a).
Key properties: Mohs hardness 1.5–2; specific gravity 3.92; Red-orange streak; Pearly to vitreous on cleavage surfaces, otherwise resinous luster; optically biaxial.
IMA symbol Get, IMA status: approved, named in 1965.
Found in an epithermal gold deposit formed in a narrow, steeply-dipping fault zone cutting interbedded Paleozoic (?) shales, argillites, and limestones, near a granodiorite intrusive (Getchell mine, Nevada, USA).
It is found associated with Orpiment, realgar, stibnite, cinnabar, galkhaite, laffittite, chabournéite, christite, lorandite, marcasite, quartz, barite, fluorite, calcite.
The name refers to the Getchell mine, Nevada, USA, where it was discovered.