Väyrynenite is a rare phosphate mineral with formula MnBe(PO4)(OH,F). It was first described in 1954 for an occurrence in Viitaniemi, Erajarvi, Finland and named for mineralogist Heikki Allan Väyrynen of Helsinki, Finland

CategoryPhosphate mineralFormula
(repeating unit)MnBe(PO4)(OH,F)IMA symbolVäy[1]Strunz classification8.BA.05Crystal systemMonoclinicCrystal classPrismatic (2/m)
(same H-M symbol)Space groupP21/aUnit cella = 5.411(5) Å,
b = 14.49(2) Å,
c = 4.73 Å;
β = 102.75°; Z = 4IdentificationColorLight pink to rose-red, salmon pink, pale gray, brownCrystal habitRare as elongated and striated prismatic crystals; fine-grained aggregatesCleavagePerfect on {010}, good on {100}, fair on {001}FractureUnevenTenacityBrittleMohs scale hardness5LusterVitreousStreakWhiteDiaphaneityTransparent to translucentSpecific gravity3.22Optical propertiesBiaxial (–)Refractive indexnα = 1.638 - 1.640 nβ = 1.658 - 1.662 nγ = 1.664 - 1.667Birefringenceδ = 0.026 - 0.027PleochroismVisible X= orangish, Y= red, Z= dark red2V angle46°–55°Dispersionr > v moderateReferences[2][3][4]

It occurs in pegmatites as an alteration of beryl and triphylite. It occurs in association with eosphorite, moraesite, hurlbutite, beryllonite, amblygonite, apatite, tourmaline, topaz, muscovite, microclineand quartz.[4]