Belomarinaite

Chemical formula: KNa(S<sup>6+</sup>O<sub>4</sub>)

Belomaryinite is a rare potassium sodium sulfate, forming colorless, vitreous aggregates in products of volcanic fumarolic activity.

## Characteristics Belomaryinite is a mineral from the sulfate group, composed of potassium, sodium, and a sulfate group. It occurs as small, anhedral (irregularly shaped) grains that form dense, granular aggregates. Individual grains reach sizes up to 0.2 mm. The mineral is colorless and transparent, with a vitreous luster. Due to its origin and small crystal size, it is primarily of scientific interest. ## Physical Properties Belomaryinite is characterized by a Mohs hardness of approximately 3.5. It has a vitreous luster and is transparent. The mineral's density is about 2.65 g/cm³. It does not exhibit fluorescence under ultraviolet light. ## Colors and Varieties The mineral is colorless. No colored or commercial varieties have been distinguished. ## History and Name Belomaryinite was first described in 2018. Its name honors Marina Belova (born 1957), a Russian crystallographer and specialist in mineral structural analysis from the Shubnikov Institute of Crystallography in Moscow. It was approved by the International Mineralogical Association (IMA) under number 2018-028. The type locality is the Yadovitaya fumarole on Tolbachik volcano in Kamchatka, Russia. ## Uses Belomaryinite has no industrial application and is solely an object of scientific interest and for advanced collectors specializing in volcanic fumarole minerals.

Properties

Mohs hardness
3.5
Luster
Vitreous
Streak
White
Density
2.65
Cleavage
None
Fracture
Uneven
Transparency
Transparent
Crystal system
Orthorhombic

Diagnostic features

## Identification Identifying belomaryinite in the field is practically impossible without specialized equipment. Identification requires advanced analytical methods such as X-ray diffraction (XRD) and chemical analysis (EDS/WDS). In a collection, it can be preliminarily identified based on its origin (Tolbachik volcano fumaroles), associated minerals, and appearance (colorless, vitreous, granular aggregates). ## Distinguishing from Similar Minerals Belomaryinite can be confused with other colorless sulfates found in the same environment, such as aphthitalite, metathenardite, or langbeinite. Aphthitalite has a similar composition but crystallizes in the trigonal system. Definitive differentiation from these minerals is only possible with X-ray analysis. ## Crystal Forms The mineral forms anhedral, irregular grains up to 0.2 mm in size. These grains coalesce into dense, granular aggregates. No well-formed, single crystals have been observed.

Geological environment

## Genesis Belomaryinite is a volcanic mineral, formed by sublimation from volcanic gases in the environment of active fumaroles. It crystallizes at high temperatures from gases rich in sulfur, sodium, and potassium. It is a product of volcanic exhalations. ## Mineral Associations This mineral co-occurs with other sulfates and halides formed under similar conditions. It is most commonly associated with: aphthitalite, langbeinite, metathenardite, halite, sylvine, hematite, tenorite, and rare minerals such as arcanite, bradaczekite, and sanjuanite. ## Localities The only confirmed occurrence of belomaryinite in the world is its type locality – the Yadovitaya ("Poisonous") fumarole on the second cone of the Northern Breach of the Great Fissure Eruption of Tolbachik volcano on the Kamchatka Peninsula, Far East, Russia.

Rarity

Very rare

For collectors

## Quality Criteria The quality of belomaryinite specimens is assessed primarily based on the richness and abundance of aggregates on the rock matrix. Since the mineral does not form well-developed crystals, its form is not an evaluation criterion. The most desirable specimens are those with dense, clearly visible clusters of colorless grains, contrasting with the matrix. Association with other rare fumarole minerals is also important. ## Popular Localities The only source of belomaryinite specimens is its type locality on Tolbachik volcano in Kamchatka. Specimens from this locality are the only ones available on the collector's market and have significant scientific value.

Care and storage

## Cleaning Belomaryinite specimens are extremely delicate and often occur as small aggregates on a matrix. Mechanical cleaning is not recommended. If necessary, compressed air (from a safe distance) can be used to remove loose dust. Avoid contact with water, as the mineral may be soluble in it. ## What to Avoid Absolutely avoid contact with water and other liquids, including cleaning agents. The mineral is sensitive to moisture and temperature changes. Protect it from direct sunlight and high temperatures. ## Storage Specimens should be stored in stable, dry conditions. The best solution is a sealed "micromount" box away from sources of moisture and temperature fluctuations. Due to its fragility, avoid vibrations and shocks.

Sources

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