Shuvalovite

Chemical formula: K<sub>2</sub>(Ca<sub>2</sub>Na)(S<sup>6+</sup>O<sub>4</sub>)<sub>3</sub>F

Shuvalovite is an extremely rare potassium, calcium, and sodium sulfate, forming microscopic, colorless crystals in volcanic gas sublimation products.

## Characteristics Shuvalovite is a sulfate mineral that visually presents as colorless, transparent crystals. It typically forms small, prismatic or tabular shapes, not exceeding 0.2 mm in length. It also occurs as fine-grained, loose aggregates. Due to its microscopic size, its features are difficult to observe without specialized equipment. ## Physical Properties The mineral is characterized by a vitreous luster and is fully transparent. Its density, calculated based on the formula and unit cell parameters, is 2.86 g/cm³. The Mohs hardness has not yet been determined. ## Colors and Varieties Shuvalovite is colorless. No colored varieties or trade names are known. ## History and Name The mineral's name honors Count Pyotr Ivanovich Shuvalov (1711–1762), a Russian statesman and field marshal who significantly contributed to the development of mining and metallurgy in the Urals. The mineral was discovered in the Naboko-1 fumarole on Tolbachik volcano (Kamchatka, Russia) and described in 2014. ## Applications Due to its extreme rarity and microscopic size, shuvalovite has no industrial applications. It is solely an object of scientific interest and a valuable acquisition for specialized micromineral collectors.

Properties

Luster
Vitreous
Streak
White
Density
2.86
Cleavage
None
Transparency
Transparent
Crystal system
Trigonal

Diagnostic features

## Identification Amateur identification of shuvalovite is practically impossible. A key diagnostic feature is its unique occurrence environment – high-temperature volcanic fumaroles. Definitive identification requires advanced analytical methods, such as X-ray diffraction (XRD) or chemical microanalysis (EDS), which allow for the determination of its crystal structure and composition. ## Distinguishing from Similar Minerals Shuvalovite can be confused with other colorless sulfates occurring in the same environment, such as langbeinite or arcanite. Distinguishing it from these minerals is only possible through laboratory analysis, which will reveal the presence of fluorine and unique proportions of potassium, calcium, and sodium. ## Crystal Forms The mineral forms short, prismatic or tabular crystals. They often occur as loose, granular aggregates or small druses on the surface of the host rock.

Geological environment

## Genesis Shuvalovite forms through sublimation, crystallizing directly from hot volcanic gases (exhalations) at temperatures of 400-450°C. It is a typical fumarolic mineral, associated with active volcanism. ## Mineral Associations This mineral co-occurs with other products of volcanic sublimation. Minerals such as langbeinite, arcanite, aphthitalite, tenorite, hematite, halite, and sylvite are found in its vicinity. ## Localities The only confirmed locality of shuvalovite in the world is the Naboko-1 fumarole, located in the main fissure crack formed during the Great Tolbachik Eruption in 2012-2013 on Tolbachik volcano (Kamchatka, Russia).

Rarity

Extremely rare

For collectors

## Quality Criteria For such a rare micromineral, the collector's value of a specimen depends on several factors. Samples with well-formed, sharp, and transparent crystals are most highly prized. The abundance of the mineral on the rock matrix and the presence of interesting associated minerals are also important. Due to their size, specimens are evaluated under a microscope. ## Popular Localities The only shuvalovite specimens come from its type locality – Tolbachik volcano in Kamchatka, Russia. This is the only source of this mineral in the world.

Care and storage

## Cleaning Shuvalovite specimens are extremely delicate and sensitive. Mechanical cleaning, including with brushes, is strongly discouraged. No liquids, especially water, should be used. ## What to Avoid The mineral is likely water-soluble and sensitive to moisture. Contact with any chemicals, sudden temperature changes, and shocks should be avoided. Store away from sources of moisture. ## Storage The safest storage method is to place the specimen in a closed, airtight "micromount" box. This protects the mineral from physical damage, dust, and changes in ambient humidity.

Sources

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