Metallic acicular crystals of the very rare mineral sorbyite from one of the only 4 localities known worldwide (Candelaria District, Mineral County, Nevada, United States of America). — Photo: David Hospital · CC BY-SA 4.0
Sorbyite
Sorbyite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula Pb₉Cu(Sb,As)₁₁S₂₆.
It crystallizes in the monoclinic crystal system. It is a member of the Madocite structural group.
Key properties: specific gravity 5.52; Black streak; Metallic luster.
IMA symbol Srb, IMA status: approved, named in 1966.
Of hydrothermal origin, in a deposit in marble (Madoc, Canada); in a hydrothermal deposit in limestone, replacing pyrite and sphalerite, with other Pb–As–Sb sulfides (Novoye, Kyrgyzstan).
It is found associated with Boulangerite, jamesonite, antimonian baumhauerite, zinkenite, semseyite, geocronite, robinsonite (Madoc, Canada); sphalerite, pyrite, galena, playfairite.
The mineral was named to honor Henry Clifton Sorby (1826–1908), English chemist and the founder of metallography.