Telluronevskite

Chemical formula: Bi<sub>3</sub>TeSe<sub>2</sub>

Telluronevskite is an extremely rare bismuth and tellurium selenide, forming tiny, tabular crystals with a metallic luster.

## Characteristics Telluronevskite is a very rare mineral from the sulfide group, classified as a bismuth and tellurium selenide. It occurs as very small, hexagonal or pseudohexagonal, tabular crystals, reaching sizes up to 0.1 mm. It also forms submillimeter aggregates. It is usually observed as inclusions in other minerals, mainly in bismuthinite. ## Physical Properties The mineral is characterized by a metallic luster and is opaque. Its Mohs hardness is 3.5. The density has been calculated at 8.45 g/cm³. It exhibits perfect cleavage in one direction. ## Colors and Varieties Telluronevskite has a steel-gray color with a slight creamy tint. No varieties are known. ## History and Name Telluronevskite was first described in 2011 by Czech and Russian scientists (Ondruš et al.). Its name refers to its chemical composition – it is the tellurium analog of nevskite (BiSe) – and to its discovery locality, the Nevskoye deposit in the Russian Far East. The mineral was approved by the International Mineralogical Association (IMA) under number 2010-063. ## Uses Due to its extreme rarity and microscopic size, telluronevskite has no practical or commercial applications. It is of purely scientific significance and is an object of interest for specialized micromineral collectors.

Properties

Mohs hardness
3.5
Luster
Metallic
Streak
Black
Density
8.45
Cleavage
Perfect on {0001}
Fracture
Micaceous
Transparency
Opaque
Crystal system
Trigonal

Diagnostic features

## Identification Identification of telluronevskite is possible only through advanced laboratory methods, such as chemical analysis using an electron microprobe (EDS/WDS) and X-ray diffraction (XRD). Visually, on a micro scale, one can observe tiny, hexagonal, tabular crystals with a metallic luster, most often in paragenesis with bismuthinite. ## Distinguishing from Similar Minerals Telluronevskite is visually indistinguishable from other rare bismuth tellurides and selenides, such as nevskite, tsumoite, or pilsenite. Definitive differentiation requires chemical composition analysis, particularly the proportions of tellurium and selenium. ## Crystal Forms The mineral forms thin, tabular crystals with a hexagonal outline, not exceeding 0.1 mm in size. It also occurs as irregular aggregates and clusters on a submillimeter scale.

Geological environment

## Genesis Telluronevskite forms under hydrothermal conditions. At its type locality (Nevskoye deposit), it was found in quartz-tourmaline veins with tungsten, tin, and bismuth mineralization. ## Mineral Associations This mineral co-occurs with bismuthinite (as inclusions), native bismuth, cosalite, pilsenite, tsumoite, arsenopyrite, pyrite, quartz, and tourmaline. ## Localities The only confirmed locality for telluronevskite worldwide is its type locality – the Nevskoye deposit, located in the Magadan Oblast in the Russian Far East.

Rarity

Extremely rare

For collectors

## Quality Criteria As an extremely rare micromineral, any analytically confirmed specimen is valuable to specialized collectors. The most highly prized specimens would be those with the largest possible (though still microscopic), well-formed crystals, clearly visible against the matrix, and with analytically confirmed identity. ## Popular Localities The only source of specimens is the Nevskoye deposit in Russia.

Care and storage

## Cleaning Due to their microscopic size and occurrence as inclusions, specimens containing telluronevskite generally do not require and should not be cleaned. Any attempt at mechanical cleaning may destroy the delicate crystals. ## What to Avoid Avoid contact with chemicals, ultrasound, and all forms of mechanical cleaning. Specimens should be protected from dust and physical damage. ## Storage Specimens containing telluronevskite, typically microminerals, are best stored in specialized "micromount" boxes. This protects the delicate crystals from damage and dust, while allowing observation under a microscope.

Sources

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