:Locality: Vasin-Myl'k Mountain, Kola, Russian Federation Size: 1.8 × 1.3 × 0.2 cm Description: Polished preparation of a sample with this rare species, a Rb-analogue of lepidolite. Voloshinite was found in rare-element granitic pegmatites at Mt. Vasin-Myl’k, in Kola Peninsula. It is closely associated with pollucite and lepidolite, trilithiolite, also typically with muscovite, albite and quartz; in some cases, associated minerals are K,Rb-feldspar, rubicline, spodumene, montebrasite, elbaite, etc. From the Type Locality. SEM image — Photo: Joan Rosell , from rosellminerals.com · CC BY-SA 4.0
Voloshinite
Voloshinite is an IMA-recognized mineral species in the silicate class, with the chemical formula Rb(LiAl₁.₅ ₀.₅)(Al₀.₅Si₃.₅)O₁₀F₂.
It crystallizes in the monoclinic crystal system (space group C2/c). It is a member of the Mica structural group.
Key properties: specific gravity 2.95; Vitreous luster; optically biaxial.
IMA symbol Vls, IMA status: approved, named in 2007.
Found in veinlets or pods inside pollucite aggregates found in rare-element granitic pegmatites, a late-stage mineral formed after pollucite.
It is found associated with Pollucite, lepidolite, muscovite, albite, quartz, K-Rb-feldspar, rubicline, spodumene, montebrasite, elbaite.
The mineral was named to honor Russian mineralogist A. V. Voloshin (b. 1937).