Outstanding white crystals of the extremely rare new mineral fluorwavellite (IMA 2015-077), the fluorine analog of wavellite, known from only four localities worldwide. From: Willard Mine, Pershing County, Nevada, United States of America. — Photo: David Hospital · CC BY-SA 4.0
Fluorwavellite
The rare fluorine analogue of wavellite — a hydrated aluminium phosphate-fluoride.
Intro adapted from Wikipedia (CC BY-SA).
Fluorwavellite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Al₃(PO₄)₂(OH)₂F·5H₂O.
It crystallizes in the orthorhombic crystal system (space group Pcnm). It is a member of the Wavellite structural group.
Key properties: Mohs hardness 3.5; specific gravity 2.3; White streak; Vitreous luster; optically biaxial.
IMA symbol Fwav, IMA status: approved, named in 2015.
A low-temperature secondary mineral.
It is found associated with Barite, fluorowardite, goethite, gypsum, kidwellite, quartz, rockbridgeite, chlorargyrite, crandallite, iangreyite, jarosite, lipscombite, metavariscite.
As the fluorine analog of wavellite and with > ½ F per formula unit.