Vavřínite

Chemical formula: Ni<sub>2</sub>SbTe<sub>2</sub>

An extremely rare nickel telluroantimonide, found exclusively in the Czech Republic as microscopic, anhedral grains.

## Characteristics Vavřínite is a very rare mineral from the sulfide group, more specifically, a nickel telluroantimonide. It occurs as anhedral (irregularly shaped) grains not exceeding 0.1 mm in size. It often forms rims or small aggregates around gersdorffite crystals. In appearance, it is inconspicuous, with a creamy-white color and a yellowish tint, especially visible in reflected light. It is a completely opaque mineral with a strong metallic luster. ## Physical Properties The hardness of vavřínite on the Mohs scale is 2.5-3, making it a soft mineral. Its density, calculated based on the chemical formula and unit cell parameters, is 8.65 g/cm³, but it has not been empirically measured. The mineral is opaque and has a metallic luster. The streak is black. ## Colors and Varieties This mineral is monochromatic – it occurs in creamy-white shades with a yellowish tint. No color or commercial varieties are known. ## History and Name Vavřínite was first described in 1993 by Z. Johan, M. Kvaček, P. Vrána, and V. Šrein. The mineral is named in honor of Ivan Vavřín (1937-1988), a Czech mineralogist and specialist in electron microprobe analysis, who worked at the Institute of Geology of the Czechoslovak Academy of Sciences. ## Applications Due to its extreme rarity and occurrence as microscopic grains, vavřínite has no industrial applications. It is solely an object of scientific interest and a valuable acquisition for specialized collectors of rare minerals.

Properties

Mohs hardness
2.5-3
Luster
Metallic
Streak
Black
Density
8.65 (obliczona)
Cleavage
None observed
Transparency
Opaque
Crystal system
Hexagonal

Diagnostic features

## Identification Identification of vavřínite with the naked eye or using basic tests is impossible. Its recognition requires advanced analytical techniques, such as chemical composition analysis using an electron microprobe (EDS/WDS) in a scanning electron microscope. Features such as color in reflected light and co-occurrence with other nickel tellurides can be indicative, but never a basis for certain identification. ## Distinguishing from Similar Minerals Vavřínite can be easily confused with other co-occurring minerals with a metallic luster, such as gersdorffite, nickeline, melonite, or altaite. Certain differentiation is only possible based on chemical analysis, which will show the simultaneous presence of nickel, antimony, and tellurium in appropriate proportions. ## Crystal Forms This mineral does not form well-developed crystals. It occurs exclusively as anhedral, irregular grains and as thin rims around other minerals, mainly gersdorffite.

Geological environment

## Genesis Vavřínite is a hydrothermal mineral. It forms in low-temperature ore veins of calcite-dolomite composition. ## Mineral Associations This mineral occurs in association with other rare tellurides, sulfides, and arsenides. It most commonly co-occurs with gersdorffite (often coating it), nickeline, ullmannite, hauchecornite, tellurohauchecornite, melonite, altaite, hessite, stützite, tellurobismuthite, cobaltite, as well as gangue minerals – calcite and dolomite. ## Localities The only confirmed locality of vavřínite in the world is its type locality: Zálesí in the Rychlebské Mountains (Rychlebské hory), in the Olomouc Region of the Czech Republic. All known specimens come from this single site.

Rarity

Extremely rare

For collectors

## Quality Criteria In the case of such a rare mineral, the primary criterion for value is the confirmation of its presence on the specimen through analysis. Specimens from the type locality are inherently the most valuable. Additional advantages may include abundance (quantity and size of microscopic grains) and the presence of well-formed associated minerals. ## Popular Localities The only locality from which vavřínite specimens originate is Zálesí in the Czech Republic. It is a "type-locality only" mineral, meaning it has not been found anywhere else in the world.

Care and storage

## Cleaning Specimens containing vavřínite, due to the microscopic size of the grains and their delicacy, should generally not be cleaned mechanically or chemically. Any attempt at cleaning risks irreversible removal or damage to the mineral. Only gentle dust removal using a stream of compressed air from a safe distance is permissible. ## What to Avoid Avoid contact with all chemicals, especially acids, which can damage it. The mineral is very soft, so it must be protected from scratching and abrasion. It should not be heated or cleaned in ultrasonic cleaners. ## Storage Specimens with vavřínite are best stored in specialized micromount boxes, which protect against dust, moisture, and mechanical damage. Storage in a stable, dry environment is crucial for preserving the integrity of the specimen.

Sources

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