Voloshinite

Chemical formula: Rb(LiAl<sub>1.5</sub>&#9744;<sub>0.5</sub>)(Al<sub>0.5</sub>Si<sub>3.5</sub>)O<sub>10</sub>F<sub>2</sub>

Voloshynite is an extremely rare mineral from the mica group, a rubidium-lithium silicate known only from one locality in the world on the Kola Peninsula.

## Characteristics Voloshynite is a mineral from the mica group, belonging to the phyllosilicates. Its unique chemical composition, rich in rubidium and lithium, makes it a mineralogical rarity. It forms colorless, transparent flakes and plates, often gathered into small, lamellar or scaly aggregates. Due to its nature, it is usually found in very small specimens, rarely exceeding a few millimeters. ## Physical properties This mineral is transparent, with a vitreous luster on crystal surfaces and a pearly luster on cleavage planes, which is typical for micas. Its density, calculated based on chemical composition and structure, is approximately 3.11 g/cm³. The hardness has not been precisely determined, but like most micas, it is a relatively soft mineral. ## Colors and varieties Voloshynite is colorless. No colored varieties or trade names are known. ## History and name The mineral is named in honor of Anatoliy Vasilyevich Voloshyn (1937–2020), a Russian mineralogist and researcher of granite pegmatites of the Kola Peninsula, where the mineral was discovered. It was officially recognized by the International Mineralogical Association (IMA) in 2009. ## Applications Due to its extreme rarity, voloshynite has no industrial applications. It is solely an object of scientific research and a valuable acquisition for specialized collectors of rare minerals and micromounts.

Properties

Luster
Vitreous, Pearly
Streak
White
Density
3.11
Cleavage
Perfect on {001}
Transparency
Transparent
Crystal system
Monoclinic

Diagnostic features

## Identification Amateur identification of voloshynite is practically impossible. A key diagnostic feature is its unique locality – it occurs exclusively in a pegmatite on Mount Vasin-Myl’k. Visually, it resembles other colorless micas. Certain identification requires advanced analytical methods, such as X-ray microanalysis (EDS/WDS), to confirm the high rubidium and lithium content. ## Distinguishing from similar minerals Voloshynite is visually indistinguishable from other colorless micas with which it co-occurs, especially polylithionite and muscovite. The only way to distinguish them is by chemical analysis. ## Crystal forms This mineral forms thin, platy or lamellar crystals with pseudohexagonal outlines. It occurs as single flakes or small, scaly aggregates.

Geological environment

## Genesis Voloshynite forms under unique geochemical conditions within highly differentiated granite pegmatites, rich in rare elements such as lithium, cesium, and rubidium. ## Mineral associations This mineral occurs in association with quartz, microcline, albite, and other rare lithium minerals, particularly polylithionite. ## Localities The only confirmed locality of voloshynite in the world is its type locality: Mount Vasin-Myl’k in the Voronye Tundra massif on the Kola Peninsula, Russia.

Rarity

Extremely rare

For collectors

## Quality criteria As a "micromount" status mineral, every, even the smallest, correctly identified specimen of voloshynite is valuable. The most desirable specimens are those showing distinct, even small, flakes on a rock matrix, preferably accompanied by other minerals from this locality. The purity and transparency of the crystals increase its value. ## Popular localities The only source of specimens is the type locality on the Kola Peninsula in Russia. Material from this location is extremely difficult to obtain.

Care and storage

## Cleaning Voloshynite specimens are extremely delicate due to their perfect cleavage. Cleaning should be kept to an absolute minimum. The safest way is to use compressed air to remove dust. Any mechanical methods, such as using a brush, risk separating the flakes. Contact with water is not recommended. ## What to avoid Avoid any shocks, impacts, and pressure, which can easily damage the fragile flakes. The mineral should be protected from contact with chemicals and acids. It should not be heated or subjected to ultrasound. ## Storage Voloshynite specimens, usually in the form of micromounts, should be stored in closed, padded boxes to protect them from mechanical damage and dust. They should be kept away from other minerals that could scratch them.

Sources

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