Plumbotellurite

Chemical formula: Pb<sup>2+</sup>Te<sup>4+</sup>O<sub>3</sub>

Plumbotellurite is a very rare lead tellurite, forming microscopic, yellow crystals with a strong, adamantine luster.

## Characteristics Plumbotellurite is a lead tellurite, occurring as very small, tabular or prismatic crystals, rarely exceeding 0.3 mm. It typically forms thin coatings and aggregates on host rocks. It is transparent to translucent, and its most characteristic features are its intensely yellow, yellow-orange, or greenish-yellow color and exceptionally strong, almost adamantine luster. ## Physical Properties This mineral is very soft, with a Mohs hardness of 2. It has a high density, approximately 7.11 g/cm³, which is typical for lead-bearing minerals. The luster is strongly resinous to adamantine. It is brittle and exhibits perfect cleavage in one direction. ## Colors and Varieties Plumbotellurite occurs in shades from canary yellow and golden yellow to yellow-orange, and sometimes greenish-yellow. No named varieties of this mineral have been distinguished. ## History and Name The name plumbotellurite directly refers to its chemical composition – it contains lead (Latin: *plumbum*) and tellurium. The mineral was first described in 1981 by G. A. Shcherbakova, L. N. Vyalsowa, and G. A. Basova based on material from the Zhana-Tyube gold mine in Kazakhstan, which is its type locality.

Properties

Mohs hardness
2
Luster
Adamantine, Resinous
Streak
Pale yellow
Density
7.11
Cleavage
Perfect on {010}
Fracture
Uneven
Transparency
Transparent to translucent
Crystal system
Orthorhombic

Diagnostic features

## Identification Plumbotellurite can be identified by its intense yellow color, very strong, resinous or adamantine luster, and occurrence as small, tabular crystals. Its high density is also a characteristic feature, although difficult to verify with such small specimens. It occurs in the oxidation zones of tellurium deposits. ## Differentiation from Similar Minerals It can be confused with other secondary yellow tellurium minerals, such as emmonsite or mackayite. Differentiation requires advanced analytical methods, such as Raman spectroscopy or chemical analysis (EDS), due to the microscopic size of the crystals. ## Crystal Forms Crystals are most often tabular, flattened parallel to {010}, or short prismatic. They usually form thin coatings, rosette-like aggregates, or occur as single, dispersed crystals on the rock surface.

Geological environment

## Genesis Plumbotellurite is a secondary mineral, formed in the oxidation zones of hydrothermal gold and tellurium deposits. It forms as a result of the weathering of primary tellurides, especially in the presence of lead minerals such as galena. ## Mineral Associations It often co-occurs with other tellurium minerals, such as native tellurium, altaite, emmonsite, mackayite, as well as galena, gold, quartz, and barite. ## Localities The most important occurrences of this very rare mineral include: - Kazakhstan - Zhana-Tyube gold mine (type locality). - United States - mines in Cochise and Pima counties in Arizona (e.g., Grand Central mine, Emerald mine) and in Teller County, Colorado (Aga mine).

Rarity

Very rare

For collectors

## Quality Criteria The most prized plumbotellurite specimens are those with well-formed, sharply terminated microcrystals of intense, canary-yellow color and strong luster. It is important that the crystals are clearly visible against a contrasting host rock background. Due to their size, specimens are evaluated under a microscope. ## Popular Localities Specimens from classic localities in Arizona (USA), such as the Emerald or Grand Central mines, are particularly sought after by collectors specializing in rare minerals and micromounts.

Care and storage

## Cleaning Plumbotellurite specimens are extremely delicate and small, therefore mechanical or chemical cleaning is not recommended. Any attempts at cleaning may destroy the microscopic crystals. It is best to leave them undisturbed. ## What to Avoid Contact with water, chemicals, ultrasound, and any tools should be strictly avoided. The crystals are very soft and brittle. They should be protected from dust, vibrations, and sudden temperature changes. ## Storage Specimens should be stored exclusively in closed, stable "micromount" boxes to protect them from mechanical damage and dust. Display should be away from sources of vibration and direct sunlight.

Sources

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