Hasanovite

Chemical formula: KNa(Mo₆+O₂)(S₆+O₄)₂

Hasanovite is a rare potassium and sodium sulfate-molybdate, forming microscopic, bright yellow crystals in volcanic exhalation products.

## Characteristics Hasanovite is a mineral from the sulfate group, chemically classified as a potassium and sodium sulfate-molybdate. It occurs as very small, prismatic crystals, not exceeding 0.2 mm in length. These crystals form radial or chaotically arranged aggregates and clusters. A characteristic feature of the mineral is its intense, bright yellow or lemon-yellow color. ## Physical Properties The mineral is transparent and characterized by a vitreous luster. Its density, calculated from crystallographic data, is 3.40 g/cm³. Hardness has not been precisely measured due to the small size of the crystals. ## Colors and Varieties Hasanovite occurs in uniform, vivid shades of yellow, from lemon to intense yellow. No color varieties or commercial forms are known. ## History and Name The mineral was officially recognized by the International Mineralogical Association (IMA) in 2019 under the number IMA2019-055. Its name commemorates Gasan (Hasan) M. Hasanov (born 1949), a Russian petrologist and volcanism researcher from the Geological Institute of the Dagestan Scientific Center of the Russian Academy of Sciences, in recognition of his contributions to the study of volcanic rocks. ## Applications Due to its extreme rarity and microscopic size, hasanovite has no industrial applications. It is solely an object of scientific interest and is valued by collectors specializing in microminerals.

Properties

Luster: Vitreous
Streak: Pale yellow
Density: 3.40
Cleavage: None
Transparency: Transparent
Crystal system: Monoclinic

Diagnostic features

## Identification Identification of hasanovite is based on several key features: occurrence in volcanic fumarole environments, characteristic bright yellow color, radial aggregates of small, prismatic crystals, and co-occurrence with other rare minerals from Tolbachik volcano. Definitive identification requires advanced analytical methods, such as X-ray diffraction (XRD) and chemical microanalysis (EDS). ## Distinguishing from Similar Minerals Hasanovite can be confused with other yellow fumarolic minerals, such as wulffite, which also occurs in the same locality. Due to the microscopic size of the crystals, visual differentiation is practically impossible and requires specialized research equipment for chemical composition analysis. ## Crystal Forms It forms elongated, prismatic crystals up to 0.2 mm long. These crystals often intergrow, forming radial aggregates or chaotic clusters.

Geological environment

## Genesis Hasanovite is a mineral of volcanic origin. It forms through sublimation, i.e., direct crystallization from hot volcanic gases (exhalations) in fumaroles. It crystallizes at temperatures of approximately 450-480°C. ## Mineral Associations This mineral occurs in association with other rare products of volcanic sublimation. The most common associated minerals include wulffite, belomarinaite, alarsite, arsmirandite, and arsenatrotitanite. ## Localities The only confirmed occurrence of hasanovite in the world is its type locality – the Arsenatnaya fumarole on the second cinder cone of the Northern Breakthrough of the Great Fissure Eruption of Tolbachik volcano on the Kamchatka Peninsula in Russia.

Rarity

Extremely rare

For collectors

## Quality Criteria The quality of collector specimens of hasanovite, being a micromineral, is assessed based on different criteria than for macroscopic specimens. The most valued samples are those with numerous, well-formed, and sharp crystals forming aesthetic, radial aggregates. The presence of associated minerals, especially rarer ones, on the same rock matrix is also highly valued. ## Popular Localities All specimens available on the collector's market come from a single location in the world – the fumarole of Tolbachik volcano in Kamchatka, Russia. This is the only source of this mineral.

Care and storage

## Cleaning Hasanovite specimens are extremely delicate and potentially water-soluble. Cleaning is not recommended. If absolutely necessary, a stream of compressed air (with great caution) or a very soft, dry brush can be used to remove dust. ## What to Avoid Contact with water, acids, detergents, and other chemicals should be strictly avoided. As a product of volcanic sublimation, the mineral may be sensitive to high humidity. It should be protected from shocks, friction, and high temperatures. ## Storage The safest storage method is to place the specimen in a sealed, plastic "micromount" box, which protects it from dust, moisture, and mechanical damage.

Sources

IMA Mineral List (CNMNC)