Väyrynenite
Appearance
Väyrynenite | |
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![]() Väyrynenite (size: 1.7 x 1.4 x 0.6 cm) | |
General | |
Category | Phosphate mineral |
Formula (repeating unit) | MnBe(PO4)(OH,F) |
Strunz classification | 8.BA.05 |
Crystal system | Monoclinic |
Crystal class | Prismatic (2/m) (same H-M symbol) |
Space group | P21/a |
Unit cell | a = 5.411(5) Å, b = 14.49(2) Å, c = 4.73 Å; β = 102.75°; Z = 4 |
Identification | |
Color | Light pink to rose-red, salmon pink, pale gray, brown |
Crystal habit | Rare as elongated and striated prismatic crystals; fine-grained aggregates |
Cleavage | Perfect on {010}, good on {100}, fair on {001} |
Fracture | Uneven |
Tenacity | Brittle |
Mohs scale hardness | 5 |
Luster | Vitreous |
Streak | White |
Diaphaneity | Transparent to translucent |
Specific gravity | 3.22 |
Optical properties | Biaxial (–) |
Refractive index | nα = 1.638 - 1.640 nβ = 1.658 - 1.662 nγ = 1.664 - 1.667 |
Birefringence | δ = 0.026 - 0.027 |
Pleochroism | Visible X= orangish, Y= red, Z= dark red |
2V angle | 46°–55° |
Dispersion | r > v moderate |
References | [1][2][3] |
Väyrynenite is a rare phosphate mineral with formula MnBe(PO4)(OH,F).[1] It was first described in 1954 for an occurrence in Viitaniemi, Erajarvi, Finland and named for mineralogist Heikki Allan Väyrynen of Helsinki, Finland.[3]
It is occurs in pegmatitess as an alteration of beryl and triphylite. It occurs in association with eosphorite, moraesite, hurlbutite, beryllonite, amblygonite, apatite, tourmaline, topaz, muscovite, microcline and quartz.[3]