Philipsbornite - Andalusia, Pozo de Los Frailes, Barranco Celejo - 1 mm. Photos from tomeikminerals.com can be used under a Creative Commons Licenese 4.0 CC-BY, as explained in: https://www.tomeikminerals.com/about-me . — Photo: Henk Smeets · CC BY 4.0
Philipsbornite
Philipsbornite is an IMA-recognized mineral species in the arsenate class, with the chemical formula PbAl₃(AsO₄)(AsO₃OH)(OH)₆.
It crystallizes in the hexagonal crystal system (space group R-3m). It is a member of the Alunite-crandallite structural group.
Key properties: Mohs hardness 4.5; specific gravity 4.1; optically biaxial.
IMA symbol Pbn, IMA status: approved, named in 1981.
A rare secondary mineral found in the oxidized zone of hydrothermal polymetallic mineral deposits.
It is found associated with Crocoite, hidalgoite, gorceixite (Tasmania); azurite, tsumcorite, bayldonite, malachite, hematite, quartz (Tsumeb, Namibia).
The mineral was named to honor Hellmut von Philipsborn (1892–1983), Professor Emeritus of Mineralogy, University of Bonn, Bonn, Germany.