Scanning electron microscope image showing hexagonal crystals of tomsquarryite associated with penriceite in Tom's quarry specimen G35033. Scale bar is 10 µm. The image is published in an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ( https://creativecommons.org/licenses/by/4.0/ ). — Photo: Peter Elliott, Ian E. Grey, William G. Mumme, Colin M. MacRae and Anthony R. Kampf · CC BY-SA 4.0
Penriceite
Penriceite is an IMA-recognized mineral species in the phosphate class, with the chemical formula [Mg(H₂O)₆][Na(H₂O)₂Al₃(PO₄)₂F₆]·H₂O.
It crystallizes in the monoclinic crystal system (space group P2_1/c). It is a member of the Aldermanite structural group.
Key properties: specific gravity 2.12; Vitreous luster; optically biaxial.
IMA symbol Prc, IMA status: approved, named in 2022.
Crystallized from groundwaters at ambient temperatures and the phosphorus derived by leaching of weakly phosphatic limestones or low-grade primary phosphorites.
It is found associated with Angastonite, minyulite, perhamite, crandallite, quartz, goethite.
The name refers to the quarry from which the studied material was collected.