Mohite

Chemical formula: Cu¹⁺₂Sn⁴⁺S²⁻₃

Mohite is a rare copper-tin sulfide, occurring as fine, gray grains in gold deposits.

## Characteristics Mohite is a rare mineral from the sulfide group, composed of copper, tin, and sulfur. It typically occurs as very fine, anhedral (irregular) grains, rarely exceeding 0.1 mm, disseminated in quartz veins. Its identification requires specialized analytical methods, such as ore microscopy and electron microprobe analysis, due to its small size and inconspicuous appearance. When observed in reflected light, it is gray. ## Physical Properties This mineral is characterized by a hardness of 4 on the Mohs scale. It is opaque and has a metallic luster. Due to the very small size of its grains, many of its physical properties, such as density, fracture, or cleavage, have not been precisely determined. ## Colors and Varieties Mohite has a uniform, gray color. No color varieties or commercial varieties are known. ## History and Name The mineral was discovered and described in 1982. Its name honors Günter H. Moh (1929–1993), a German mineralogist and experimentalist from the University of Heidelberg, for his contributions to research on tin sulfides and sulfosalts. ## Applications Mohite has no industrial application. Its significance is purely scientific and collectible, although due to its rarity and microscopic size, it is primarily of interest to specialized collectors of rare minerals.

Properties

Mohs hardness: 4
Luster: Metallic
Density: 0
Transparency: Opaque
Crystal system: Monoclinic

Diagnostic features

## Identification Identification of mohite in field conditions is impossible. Recognition relies solely on advanced laboratory techniques, such as EDS/WDS analysis in an electron microscope, which confirms its chemical composition (presence of copper, tin, and sulfur). In a reflected light ore microscope, it is gray and shows no pleochroism. ## Differentiation from Similar Minerals It can be confused with other fine-grained tin sulfides, such as stannite, kesterite, or chernyiite, with which it often co-occurs. Differentiation from these requires chemical analysis to determine the exact proportions of metals. ## Crystal Forms Mohite forms only very fine, irregular grains, often intergrown with other minerals. Well-formed crystals are not observed.

Geological environment

## Genesis Mohite is a mineral of hydrothermal origin. It forms in low-temperature, volcanogenic gold, silver, and tellurium veins. It crystallizes in a sulfur- and tin-rich environment, along with other sulfides. ## Mineral Associations This mineral co-occurs with other sulfides and tellurides. It is most commonly associated with: stannite, kesterite, pyrite, chalcopyrite, galena, sphalerite, as well as gold and silver tellurides such as sylvanite, petzite, or hessite. It occurs in association with quartz, calcite, and barite. ## Localities The type and most important locality from which mohite was described is the Kockbulak gold deposit in the Tashkent region of Uzbekistan. This is the only confirmed and well-documented occurrence of this mineral in the world.

Rarity

Very rare

For collectors

## Quality Criteria The quality of a mohite specimen depends solely on the confirmation of its presence through analysis and on the richness of its association with other rare minerals on the same rock fragment. Since the grains are microscopic, aesthetic values do not play a role. The most valuable samples come from the type locality (Kockbulak), with accurately documented analysis. ## Popular Localities The only source of collectible specimens is the Kockbulak mine in Uzbekistan. Specimens from this locality are highly sought after by collectors specializing in rare minerals and "micromounts."

Care and storage

## Cleaning Specimens containing mohite, due to the microscopic size of the grains, generally do not require and should not be mechanically cleaned. Any attempts at cleaning may remove or damage the fine mineral grains. If dust removal is necessary, compressed air can be used from a safe distance. ## What to Avoid Avoid contact with chemicals, acids, and detergents that may react with sulfides. The mineral is stable, but it should be protected from abrasion and mechanical damage. ## Storage Mohite specimens are best stored under stable conditions, in enclosed "micromount" boxes, to protect them from dust and damage. A label with precise locality information is crucial for scientific and collectible value.