Mitryaevaite
Mitryaevaite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Al₅(PO₄)₂[(P,S)O₃(OH,O)]₂F₂(OH)₂·14.5H₂O.
It crystallizes in the triclinic crystal system (space group P-1).
Key properties: specific gravity 2.02; White streak; Vitreous, dull in massive nodules luster; optically biaxial.
IMA symbol Myv, IMA status: approved, named in 1991.
Found as a secondary mineral in fractures and veinlets, in altered and oxidized vanadium-bearing phosphatic black shales.
It is found associated with Minyulite, crandallite, gorceixite, wavellite, variscite, evansite, aluminite, meta-aluminite, kaolinite, hewettite, gypsum.
The mineral was named to honor Dr. Nonna Mikhailovna Mitryaeva (1920–), for her contributions to the mineralogy of Kazakhstan.