Tellurantimony

Chemical formula: Sb<sup>3+</sup><sub>2</sub>Te<sup>2-</sup><sub>3</sub>

Tellurantimony is a rare antimony telluride, forming thin, platy crystals with a metallic luster and silvery-white color.

## Characteristics Tellurantimony is a rare mineral from the telluride group, chemically classified as antimony telluride. It occurs as small, tabular or platy crystals, often forming radial or lamellar aggregates. Its appearance is typically metallic, with a characteristic silvery-white color, which on fresh surfaces may have a slightly pink or yellow tint. Over time, its surface may dull and acquire a darker, grayish tarnish. ## Physical Properties This mineral is very soft; its Mohs hardness is only 2. It is opaque and possesses a strong, metallic luster. Due to its platy structure and perfect cleavage, it is very brittle and easily susceptible to mechanical damage. Its density is relatively high, approximately 6.45 g/cm³. ## Colors and Varieties Tellurantimony does not have diverse color varieties. Its color is consistent, ranging from tin-white to silvery-white, sometimes with a reddish or yellowish tint. On weathered surfaces, it may be covered with a dark gray or black tarnish. ## History and Name The mineral's name, given in 1940 by Clifford Frondel and Donald M. Moore

Properties

Mohs hardness
2
Luster
Metallic
Streak
Gray
Density
6.44 - 6.46
Cleavage
Perfect on {0001}
Fracture
Uneven
Transparency
Opaque
Crystal system
Trigonal

Diagnostic features

## Identification Diagnostic features of tellurantimony include its silvery-white color with a metallic luster, very low hardness (2 on the Mohs scale), and perfect cleavage in one direction, which causes the mineral to easily split into thin, flexible, but not elastic lamellae. Its characteristic forms of occurrence – thin, tabular crystals and platy aggregates – are also distinctive. ## Distinguishing from Similar Minerals Tellurantimony can be confused with other metallic minerals of similar color, such as stibnite, native bismuth, tellurobismuthite, or tetradymite. It is distinguished from stibnite by the absence of striations on crystal surfaces and a different crystal habit. It is difficult to distinguish visually from native bismuth, but bismuth often has a reddish tarnish and is slightly harder. Definitive differentiation from tellurobismuthite and tetradymite usually requires advanced chemical analysis (EDS/WDS). ## Crystal Forms Tellurantimony crystallizes in the trigonal system, forming thin, hexagonal crystals with a tabular habit. It most often occurs as platy, scaly, or radial aggregates. It rarely forms single, well-developed crystals.

Geological environment

## Genesis Tellurantimony is a hydrothermal mineral. It forms in medium to high-temperature ore veins, rich in tellurium and antimony, and poor in sulfur. It typically forms in association with native gold and other tellurides. ## Mineral Associations This mineral often co-occurs with minerals such as: native gold, native tellurium, altaite, hessite, petzite, sylvanite, tetradymite, stibnite, pyrite, chalcopyrite, sphalerite, and quartz. ## Localities The most important and historical occurrences of tellurantimony include the Mattagami Lake mine in Quebec, Canada, and the Sanda mine in Hyōgo Prefecture, Japan. It is also known from the Boliden mine in Sweden, the Co-O mine in the Philippines, as well as several localities in the United States (Colorado, California) and Australia (Western Australia).

Rarity

Rare

For collectors

## Quality Criteria The most valuable specimens for collectors are those with well-formed, sharp crystals with a distinct hexagonal outline and a strong metallic luster. Rich platy aggregates on a contrasting rock matrix are also highly prized, especially in association with native gold or other rare tellurides. The size of crystals and aggregates is crucial, as most specimens are microscopic or very small. ## Popular Localities Specimens from classic localities, such as the Mattagami Lake mine in Canada or the Sanda mine in Japan, are considered historically important and sought after by collectors. Good quality microcrystals also come from some mines in the USA and Australia.

Care and storage

## Cleaning Tellurantimony is extremely soft and delicate, so it must be cleaned with the utmost care. For dust removal, it is best to use only compressed air. Any mechanical contact, even with a soft brush, can scratch or damage the mineral's surface. Avoid water and all chemical agents. ## What to Avoid This mineral is sensitive to air and moisture, which cause it to tarnish and oxidize. It should be protected from sudden temperature changes, direct sunlight, and all chemicals, including acids and bases. Due to its perfect cleavage and low hardness, it is very susceptible to mechanical damage – scratches and cracks. ## Storage Tellurantimony specimens should be stored under stable conditions, preferably in closed, padded boxes or display cases, to limit contact with air and dust. It should be stored separately from harder minerals to avoid scratches. Display should be in enclosed cabinets, away from heat sources and direct light.

Sources

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