Picture width 2.0 mm. Collection and photograph Christian Rewitzer. From: Nuestra Señora de las Alcantarillas mine, Belalcázar, Córdoba, Andalusia, Spain. — Photo: Christian Rewitzer · CC BY-SA 3.0
Preisingerite
Preisingerite is an IMA-recognized mineral species in the arsenate class, with the chemical formula Bi₃O(AsO₄)₂(OH).
It crystallizes in the triclinic crystal system (space group P-1).
Key properties: Mohs hardness 3.5–4.5; specific gravity 6; White streak; Subadamantine to adamantine luster; optically biaxial.
IMA symbol Psg, IMA status: approved, named in 1981.
A rare secondary mineral found in the oxidized zone of some arsenic-bearing hydrothermal mineral deposits.
It is found associated with Rooseveltite, mixite, beudantite, bismuthite (Argentina); bismutostibiconite, atelestite, beyerite (Clara mine, Germany).
The mineral was named to honor Anton Preisinger (1925–), Professor of Mineralogy, University of Technology, Vienna, Austria.