Steklite

Chemical formula: KAl(S⁶⁺O₄)₂

Steklite is a rare potassium aluminum sulfate, occurring as small, colorless to white crystals in volcanic environments.

## Characteristics Steklite is a mineral from the sulfate group, chemically corresponding to anhydrous potassium aluminum sulfate. It occurs extremely rarely, forming very small, tabular or platy crystals, usually with a hexagonal outline. It is most often observed as coatings, aggregates, and clusters on lavas or within volcanic fumaroles. Crystals are typically colorless to white and do not exceed tenths of a millimeter in size. ## Physical Properties Steklite crystals are characterized by a vitreous luster. Due to the small size of the crystals, precise determination of many physical properties, such as hardness or density, is difficult. The mineral is non-hygroscopic and insoluble in water. ## Colors and Varieties Steklite is usually colorless or white. No colored varieties are distinguished. ## History and Name The mineral's name comes from the Russian word "стекло" (stieklo), meaning "glass," which refers to the vitreous luster of its crystals. It was first described in 1989 by L.P. Vergasova, S.K. Filatov, E.K. Serafimova, and T.F. Semenova based on material found in the products of fumarolic activity of the Tolbachik volcano in Kamchatka, Russia. ## Applications Steklite has no industrial or commercial applications. Its significance is purely scientific and as a collector's item, as a rare and specific product of volcanic processes.

Properties

Mohs hardness
2.5
Color
colorless
Luster
Vitreous
Streak
white
Density
2.792
Cleavage
parallel to {001}
Fracture
Micaceous
Transparency
Transparent
Crystal system
Trigonal

Diagnostic features

## Identification Identification of steklite is possible almost exclusively using advanced analytical methods, such as X-ray diffraction (XRD) and chemical microanalysis (EDS/WDS). Visual identification in the field or even in a collection is practically impossible due to the microscopic size of the crystals and their resemblance to many other volcanic sublimation products. ## Distinguishing from Similar Minerals Steklite can be confused with other sulfates found in fumarolic environments, such as alunogen, millosevichite, alunite, or langbeinite. Differentiation requires specialized laboratory equipment. Its non-hygroscopic nature distinguishes it from some hydrated sulfates. ## Crystal Forms Steklite forms very small, thin, tabular crystals with a hexagonal outline. They occur as single, scattered flakes or form small, rosette-like aggregates and coatings on rock surfaces.

Geological environment

## Genesis Steklite is a mineral of volcanic origin. It forms as a result of fumarolic activity, where it crystallizes directly from hot volcanic gases (sublimation) at temperatures ranging from 100 to 350°C. It is a product of the reaction of sulfur-rich exhalations with aluminosilicates present in volcanic rocks. ## Mineral Associations This mineral co-occurs with other products of volcanic fumaroles. At its type locality (Tolbachik volcano), it was found in association with hematite, halite, sylvite, tenorite, langbeinite, aphthitalite, anglesite, and cotunnite. ## Localities Confirmed occurrences of steklite are extremely rare. The most important and type locality is the fumaroles of the Great Fissure Eruption of the Tolbachik volcano on the Kamchatka Peninsula in Russia. It has also been identified in a nickel ore mine near the city of Severomorsk in the Murmansk Oblast, Russia.

Rarity

Very rare

For collectors

## Quality Criteria Due to the microscopic nature of the mineral, collectible specimens are exclusively "micromounts" – fragments of host rock with crystals visible under a microscope. The most highly valued specimens are those with well-formed, sharp crystals of hexagonal outline, forming rich coatings or aesthetic groups. Contrast with the substrate (matrix) and the presence of associated minerals are also important. ## Popular Localities The only source of collectible steklite specimens is its type locality – the Tolbachik volcano in Kamchatka, Russia. Specimens from this location are highly sought after by collectors specializing in rare minerals and micromounts.

Care and storage

## Cleaning Steklite specimens are extremely delicate and small, so mechanical or chemical cleaning is not recommended. Any attempts at cleaning may destroy the tiny crystals. It is best to leave the specimen undisturbed. ## What to Avoid Contact with water and chemicals should be strictly avoided. Although the mineral is described as insoluble, liquids can destroy delicate aggregates or damage the host rock. It should be protected from shocks, ultrasound, and high temperatures. ## Storage Specimens should be stored under stable conditions, in closed, padded "micromount" boxes, to protect them from dust, moisture, and mechanical damage. They should not be exposed to direct sunlight.

External references

Sources

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