Home > Metallic Minerals – September 17 > MS1442 Galkhaite

Galkhaite - Sold

Twin Creeks mine
Humboldt County
Nevada
U.S.A.

1.7 by 1.6 by 0.7 cm – Thumbnail specimen (fits into a 2.5 cm cube)

Galkhaite is a complex sulfosalt mineral of the tennantine group with a complex scientific history. Galkhaite was named after its co-type locality: Gal-Khaya, Russia (Grudzen et al., 1972). Originally the mineral formula was given as HgAsS₂. Further study by Chen & Symański (1982) and other workers showed further chemical complexity, leading to formula (Cs,Tl,□)(Hg,Cu,Zn,Tl)₆(As,Sb)₄S₁₂. Ultimately Biagioni et al. (2014) refined three more crystal structures, and justified an ideal formula of [Hg₅Cu]CsAs₄S₁₂.

This is a rare galkhaite specimen from the Twin Creek mine in Nevada. Galkhaite forms cubo-octahedral crystals to 3 mm with microcrystals of stibnite. This is a different locality than the Getchell mine, also in Nevada, which has produced most galkhaite seen on the mineral market.