Sarvodaite

Chemical formula: Al₂(S⁶⁺O₄)₃·5H₂O

Sarvodaite is a very rare, hydrated aluminum sulfate, forming soft, white efflorescences and fibrous aggregates, discovered in Tajikistan.

## Characteristics Sarvodaite is a sulfate mineral, chemically a hydrated aluminum sulfate. It occurs as very fine, flexible fibers up to 1 mm long and up to 1 µm thick, which form felt-like or cotton-like aggregates. It is also observed in the form of thin coatings and crusts. It is an extremely delicate and brittle mineral. ## Physical Properties Sarvodaite is characterized by very low hardness, only 1-1.5 on the Mohs scale, which means it is extremely soft. Its calculated density is 2.33 g/cm³. The mineral exhibits a silky luster. It is opaque. ## Colors and Varieties This mineral is white. No colored or commercial varieties have been distinguished. ## History and Name Sarvodaite was approved as a new mineral species by the International Mineralogical Association (IMA) in 2021. Its name comes from the historical village of Sarvoda, which was located near the discovery site and is now submerged by the waters of a hydroelectric power plant reservoir. The mineral was discovered in the Fan-Yagnob coal deposit in Tajikistan. ## Uses Due to its extreme rarity, small size, and delicacy, sarvodaite has no industrial application. It is solely an object of scientific and collecting interest for specialized collectors of rare minerals.

Properties

Mohs hardness
1-1.5
Luster
Silky
Streak
White
Density
2.33
Cleavage
{100}
Fracture
Splintery
Transparency
Opaque
Crystal system
Monoclinic

Diagnostic features

## Identification Sarvodaite can be identified by its characteristic mode of occurrence – white, felt-like or woolly aggregates of fine fibers. Its extreme softness (hardness 1-1.5) and delicacy are key features. It reacts with water. Final identification requires advanced analytical methods, such as X-ray diffraction (XRD). ## Distinguishing from Similar Minerals It can be confused with other white, fibrous sulfates formed under similar conditions, such as epsomite, halotrichite, or alunite. Distinguishing it from them with the naked eye is practically impossible and requires chemical or crystallographic analysis. Unlike many of them, sarvodaite is an aluminum sulfate without other cations. ## Crystal Forms Sarvodaite crystals are in the form of very fine, flexible fibers that aggregate into tangled, felt-like or woolly masses. It also forms thin crusts and coatings on the host rock.

Geological environment

## Genesis Sarvodaite is a secondary mineral that forms as a result of post-magmatic (fumarolic) processes associated with underground fires in coal deposits. It crystallizes from sulfur- and aluminum-rich gases in lower temperature zones. ## Mineral Associations This mineral co-occurs with native sulfur, salammoniac, millosevichite, and other rare sulfates formed in the environment of burning coal dumps. ## Localities The only confirmed locality of sarvodaite in the world is its type locality – the Kukhi-Malik area within the Fan-Yagnob coal deposit, in the Ayni district, Sughd Province, Tajikistan.

Rarity

Extremely rare

For collectors

## Quality Criteria The quality of a sarvodaite specimen is primarily assessed based on the abundance and purity of the white, felt-like aggregates on the host rock (matrix). The richer and better-formed the coating, the more valuable the specimen. Contrast with the matrix and the presence of associated minerals are also important. ## Popular Localities The only known and most prized specimens come from the type locality in Tajikistan. This mineral is not known from any other places in the world.

Care and storage

## Cleaning Sarvodaite specimens should not be cleaned mechanically or chemically. Due to its extreme brittleness and water solubility, any attempt at cleaning risks irreversible destruction of the mineral. Dust should only be removed with a very gentle stream of compressed air from a long distance. ## What to Avoid Contact with water and other liquids that can dissolve it must be strictly avoided. The mineral is very sensitive to moisture, so it should be stored in a dry environment. It should be protected from shocks, touch, and any mechanical pressure. ## Storage Sarvodaite requires storage under specialized conditions. It is best to place it in a sealed, closable "micromount" box away from sources of moisture and vibrations. It is recommended to add a desiccant (e.g., silica gel) to the container.

External references

Sources

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