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Väyrynenite

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Väyrynenite
Väyrynenite (size: 1.7 x 1.4 x 0.6 cm)
General
CategoryPhosphate mineral
Formula
(repeating unit)
MnBe(PO4)(OH,F)
IMA symbolVäy[1]
Strunz classification8.BA.05
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
(same H-M symbol)
Space groupP21/a
Unit cella = 5.411(5) Å,
b = 14.49(2) Å,
c = 4.73 Å;
β = 102.75°; Z = 4
Identification
ColorLight pink to rose-red, salmon pink, pale gray, brown
Crystal habitRare as elongated and striated prismatic crystals; fine-grained aggregates
CleavagePerfect on {010}, good on {100}, fair on {001}
FractureUneven
TenacityBrittle
Mohs scale hardness5
LusterVitreous
StreakWhite
DiaphaneityTransparent to translucent
Specific gravity3.22
Optical propertiesBiaxial (–)
Refractive indexnα = 1.638 - 1.640 nβ = 1.658 - 1.662 nγ = 1.664 - 1.667
Birefringenceδ = 0.026 - 0.027
PleochroismVisible X= orangish, Y= red, Z= dark red
2V angle46°–55°
Dispersionr > v moderate
References[2][3][4]

Väyrynenite is a rare phosphate mineral with formula MnBe(PO4)(OH,F).[2] It was first described in 1954 for an occurrence in Viitaniemi, Erajarvi, Finland and named for mineralogist Heikki Allan Väyrynen of Helsinki, Finland.[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, microcline and quartz.[4]

References

[edit]
  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ a b Väyrynenite on Mindat.org
  3. ^ Väyrynenite data on Webmineral
  4. ^ a b c Väyrynenite data from the Handbook of Mineralogy