Galkhaite

Galkhaite is a rare and chemically complex sulfosalt mineral from a group of natural thioarsenites. Its formula is (Cs,Tl)(Hg,Cu,Zn)₆(As,Sb)₄S₁₂, making the mineral the only known natural Cs-Hg and Cs-As phase. It occurs in Carlin-type hydrothermal deposits.^[2][3][4][5]

Galkhaite
Galkhaite crystals to 3 mm on matrix, Getchell Mine, Nevada.
General
Category	Sulfosalt minerals
Formula	(Cs,Tl)(Hg,Cu,Zn)6(As,Sb)4S12
IMA symbol	Gkh[1]
Strunz classification	2.GB.20
Crystal system	Cubic
Crystal class	Hextetrahedral (43m) H-M symbol: (4 3m)
Space group	I43m