Tikhonenkovite

Chemical formula: SrAlF<sub>4</sub>(OH)·H<sub>2</sub>O

Tikhonenkovite is a rare strontium aluminum fluoride, forming tiny, colorless or white crystals, found in the oxidation zones of celestine deposits.

## Characteristics Tikhonenkovite is a hydrated strontium aluminum fluoride. It occurs as very small, tabular or prismatic crystals, rarely exceeding 1-2 mm. Most often, it forms thin crusts, coatings, or rosette-like aggregates. Crystals can be colorless, white, or grayish, often with a pearly or vitreous luster on their faces. ## Physical Properties This mineral is characterized by a relatively low hardness, approximately 3.5 on the Mohs scale. Its crystals are transparent to translucent. It has perfect cleavage in one direction, causing it to easily split into thin lamellae. The density of tikhonenkovite is approximately 3.25 g/cm³. ## History and Name The mineral was discovered in 1964 on Mount Moldog-Too in Kyrgyzstan. Its name commemorates the Russian mineralogist and geologist Igor Petrovich Tikhonenkov (1927–1961), a specialist in rare metal deposits and alkaline magmatic complexes.

Properties

Mohs hardness
3.5
Luster
Vitreous, Pearly
Streak
White
Density
3.25
Cleavage
Perfect on {001}
Fracture
Uneven
Transparency
Transparent to translucent
Crystal system
Monoclinic

Diagnostic features

## Identification Characteristic features of tikhonenkovite include its occurrence as small, tabular crystals with a pearly luster, perfect cleavage, and paragenesis with celestine and other fluorides. Due to the small size of the crystals, final identification usually requires advanced analytical methods, such as X-ray diffraction (XRD). ## Distinguishing from similar minerals Tikhonenkovite can be confused with other secondary fluoride minerals, such as gearksutite or prosopite, which may occur in similar environments. Differentiation with the naked eye is practically impossible and requires chemical or crystallographic analysis. ## Crystal forms Crystals are most often tabular, flattened along the direction of perfect cleavage. They also form aggregates in the shape of rosettes, spherulites, and thin crusts and coatings on other minerals.

Geological environment

## Genesis Tikhonenkovite is a secondary mineral, forming in the oxidation (weathering) zones of hydrothermal deposits rich in strontium, especially celestine (strontium sulfate) deposits. It forms as a result of the reaction of fluorine-rich solutions with minerals containing strontium and aluminum. ## Mineral associations It most commonly co-occurs with celestine, strontianite, fluorite, quartz, calcite, as well as other rare fluorides such as gearksutite and prosopite. ## Localities The most important occurrences of this mineral are the type locality on Mount Moldog-Too in Kyrgyzstan and the celestine deposit near the village of Siersza in Turkmenistan. It is also known from several other places worldwide where similar geological conditions exist.

Rarity

Very rare

For collectors

## Quality criteria Due to its rarity and small crystal size, specimens with well-formed, visible crystals, preferably in the form of aesthetic rosettes or groups, are most valued. Association with other minerals, especially with well-formed celestine crystals, is also important. The purity and transparency of the crystals increase the value of the specimen, but these are secondary characteristics compared to the mere presence of well-defined crystalline forms. ## Popular localities The most known and valued specimens come from the type locality in Kyrgyzstan and from the deposit in Turkmenistan.

Care and storage

## Cleaning Specimens should be cleaned only very carefully, using a soft brush to remove dust. Due to its low hardness and perfect cleavage, ultrasonic cleaners and mechanical cleaning should be avoided. Contact with water should be kept to a minimum. ## What to avoid Avoid contact with acids and other chemicals that can damage the mineral. It is susceptible to scratches and impacts. It should not be heated or exposed to sudden temperature changes. ## Storage It is recommended to store specimens in separate, padded collector's boxes to protect them from mechanical damage and contact with harder minerals. They should be protected from dust and moisture.

Sources

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