Fluorowardite
Fluorowardite is an IMA-recognized mineral species in the phosphate class, with the chemical formula NaAl₃(PO₄)₂(OH)₂F₂·2H₂O.
It crystallizes in the tetragonal crystal system (space group P4_12_12). It is a member of the Wardite structural group.
Key properties: Mohs hardness 5; specific gravity 2.706; White streak; Vitreous to pearly luster; optically uniaxial.
IMA symbol Fwd, IMA status: approved, named in 2012.
A secondary phase, in a F-rich secondary phosphate assemblage.
It is found associated with Alunite, barite, cacoxenite, chlorargyrite, fluorapatite, goethite, gorceixite (F-rich), iangreyite, iodargyrite, jarosite, kidwellite.
The fluorine analog of wardite; with the prefix “fluoro-” rather than “fluor-” to make pronunciation more straightforward.