Gallobeudantite
The gallium analogue of beudantite — a secondary mineral where rare gallium replaces iron, described in 1996.
Intro adapted from Wikipedia (CC BY-SA).
Gallobeudantite is an IMA-recognized mineral species in the arsenate class, with the chemical formula PbGa₃(AsO₄)(SO₄)(OH)₆.
It crystallizes in the hexagonal crystal system (space group R3m). It is a member of the Alunite-beudantite structural group.
Key properties: Mohs hardness 4; specific gravity 4.87; White to pale yellow streak; Vitreous luster; optically uniaxial.
IMA symbol Gbdn, IMA status: approved, named in 1994.
Found as a rare secondary mineral in vugs in oxidized ore from a dolostone-hosted hydrothermal polymetallic ore deposit.
It is found associated with Stolzite, mercurian silver, otjisumeite, gallian beudantite, gallian hidalgoite, scorodite, hematite, goethite, reniérite, gallite, gallian tennantite.
The name refers to its predominant gallium content as a member of the beudantite group.