Väyrynenite

Class: Phosphates, arsenates, vanadates

An alteration product of beryl and triphylite in a complex zoned granite pegmatites (Anthony et al., 2001—2005). One of the rarest gemstones.

Väyrynenite — specimen 0115, photo © NMNHS

Original description: ‘Väyrynenit’ Volborth, A., Stradner, E., 1954. Väyrynenit BeMn[PO4](OH), ein neues Mineral — Anzeiger der Österreichischen Akademie der Wissenschaften Mathematisch-Natur Wissenschaftliche Klasse 2: 21—23 [view in ‘Library’].

Type locality: Viitaniemi pegmatite, Eräjärvi, Orivesi, Finland.

Type material: National Museum of Natural History, Smithsonian Institution, Washington, DC, USA, R11807 (Anthony et al., 2001—2005).

Etymology: honours Professor Heikki Allen Väyrynen, Finnish mineralogist.

Distribution: crystals mainly from Chitral Valley, Pakistan (Anthony et al., 2001—2005).

Chemistry

BeMn2+(PO4)(OH,F)

Essential elements: hydrogen (H), beryllium (Be), oxygen (O), fluorine (F), phosphorus (P), manganese (Mn).

Crystal data

Crystallography: monoclinic — prismatic. Crystal habit: rare prismatic crystals, elongated and striated along [001], to 6 cm; typically in fine-grained aggregates (Anthony et al., 2001—2005).

Physical properties

Cleavage: on {010}, perfect; on {100}, good; on {001}, distinct (Anthony et al., 2001—2005). Fracture: uneven (Anthony et al., 2001—2005). Tenacity: brittle (Arem, 1987: 198). Hardness: 5 (Arem, 1987: 198). Density: 3.22 g/cm3 (Anthony et al., 2001—2005). Luminescence: none reported (Arem, 1987: 198).

Optical properties

Colour: rose-red, pale pink, pink, brownish pink, pale grey; pink to colourless in transmitted light (Anthony et al., 2001—2005). Diaphaneity: transparent to translucent (Anthony et al., 2001—2005). Lustre: vitreous (Arem, 1987: 198). Refractive index: 1.638—1.662 — anisotropic [biaxial (-)] (Anthony et al., 2001—2005). Birefringence: 0.026—0.027. Dispersion: moderate (Anthony et al., 2001—2005). Pleochroism: X = orangish; Y = red; Z = dark red (Anthony et al., 2001—2005).

Material from ‘Repository’

1 specimen: 0115 — 0.08 ct, Pakistan.

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