Natalyite

Chemical formula: NaV<sup>3+</sup>Si<sub>2</sub>O<sub>6</sub>

Natalyite is a rare, green sodium-vanadium pyroxene, forming fine grains in metamorphic rocks.

## Characteristics Natalyite is a mineral from the pyroxene group, a sodium and vanadium silicate. It typically occurs as very fine, anhedral (lacking crystal faces) grains, usually not exceeding 0.25 mm in size. It rarely forms aggregates. Its most characteristic feature is an intense, emerald-green color. ## Physical Properties This mineral is characterized by a hardness of approximately 6 on the Mohs scale and a density of 3.56 g/cm³. It has a vitreous luster and is translucent. It exhibits good cleavage in two directions, typical for pyroxenes. ## Colors and Varieties Natalyite occurs in one characteristic color – emerald-green. No color varieties or commercial names are known. ## History and Name The mineral was first described in 1985 by A. A. Zolotarev, L. F. Perekalin, V. V. Zhdanov, and E. V. Vasiliev. Its name comes from the Russian crystallographer Natalia Vasilievna Belova (1917-1983), in recognition of her contribution to the study of silicate structures. It was approved by the International Mineralogical Association (IMA) in 1984. ## Applications Due to its extreme rarity and microscopic crystal sizes, natalyite has no industrial applications. It is solely an object of scientific interest and a collector's item for specialized micromineral collectors.

Properties

Mohs hardness
6
Luster
Vitreous
Streak
White
Density
3.56
Cleavage
Good on {110}
Fracture
Uneven
Transparency
Translucent
Crystal system
Monoclinic

Diagnostic features

## Identification Identifying natalyite under amateur conditions is practically impossible due to the microscopic size of its grains. It is distinguished by its intense, emerald-green color and its co-occurrence with other rare vanadium minerals. Definitive identification requires advanced analytical methods, such as X-ray microanalysis (EDS/WDS). ## Distinguishing from similar minerals It can be confused with other green minerals found in similar environments, such as chromian diopside, kosmochlor, or jadeite. Differentiation is based on chemical composition – natalyite is the only one of these that contains vanadium as the dominant component in that structural position. Kosmochlor is its chromium analogue, and jadeite is its aluminum analogue. ## Crystal Forms Natalyite forms exclusively anhedral, irregular grains, usually smaller than 0.25 mm, dispersed in the host rock. Well-formed crystals are not observed.

Geological environment

## Genesis Natalyite forms under conditions of high-pressure metamorphism. Its typical occurrence environment is carbon- and vanadium-rich black shales that have undergone transformation in the eclogite facies. It is a product of reactions between vanadium minerals and sodium minerals under specific pressure and temperature conditions. ## Mineral Associations This mineral co-occurs with other minerals typical of vanadium-rich metamorphic rocks. It is most often associated with graphite, quartz, rutile, omphacite-group pyroxenes, phengite (a muscovite variety), as well as other rare vanadium minerals like goldmanite (vanadium garnet) or karelianite. ## Localities The only confirmed and well-documented occurrence of natalyite in the world (type locality) is the Pereval marble deposit in the Sludyanka region, near Lake Baikal in Russia. This is a classic locality for many rare metamorphic minerals.

Rarity

Very rare

For collectors

## Quality Criteria The quality of a natalyite specimen is primarily assessed based on the abundance and size of the grains within the host rock. The most desirable specimens are those where numerous, intensely green grains are visible, forming distinct clusters. Contrast with a light host rock (e.g., marble) also enhances visual appeal. Due to the microscopic nature of the mineral, purity and form are not key criteria. ## Popular Localities The only source of collector specimens is the type locality – the Pereval deposit in Russia. All available specimens on the market originate from this single location.

Care and storage

## Cleaning Specimens containing natalyite, which are usually microminerals within a host rock, do not require cleaning. Any attempts at mechanical or chemical cleaning may damage or destroy the fine mineral grains. If necessary, compressed air can be used to remove dust. ## What to avoid Avoid contact with chemicals, acids, and ultrasonic cleaners. The mineral is stable, but due to its rarity and small size, particular caution should be exercised. ## Storage Specimens should be stored in stable conditions, away from dust and vibrations. The best solution is a dedicated "micromount" box, which protects the specimen from mechanical damage and contamination.

Sources

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