Tatarinovite

Chemical formula: Ca₃Al(S⁶⁺O₄)[B(OH)₄](OH)₆·12H₂O

Tatarinovite is a very rare mineral from the ettringite group, a hydrated calcium and aluminum sulfate-borate, discovered in Russia.

## Characteristics Tatarinovite is a mineral from the ettringite group, occurring as hexagonal, prismatic crystals up to 0.5 mm long. It forms colorless, transparent acicular crystals, often gathered in radial aggregates or forming crystalline druses on the surface of the host rock. Due to the small size of the crystals, its visual characteristics are difficult to assess without magnification. ## Physical Properties Tatarinovite crystals exhibit a vitreous luster. This mineral is very soft, with a Mohs hardness of only 2. It is also very brittle. The calculated density is 1.83 g/cm³. ## Colors and Varieties Tatarinovite is colorless. No colored varieties are known. ## History and Name The mineral was approved by the IMA in 2016 (IMA2016-056). Its name honors the Russian mineralogist and geologist Pavel Mikhailovich Tatarinov (1895–1976), who made significant contributions to the study of ore deposit geology. It was discovered in a nickel, copper, and iron mine in Norilsk, Siberia. ## Applications Tatarinovite has no industrial application. It is of interest only to collectors specializing in rare minerals and to scientists.

Properties

Mohs hardness
3
Color
Colorless
Luster
Vitreous
Streak
White
Density
1.79
Cleavage
on (100)
Fracture
Uneven
Transparency
Transparent
Crystal system
Hexagonal

Diagnostic features

## Identification Identification of tatarinovite is primarily based on its appearance – it forms small, colorless, acicular crystals in radial aggregates. Key factors include its association with the locality (Norilsk area) and co-occurring minerals. Final confirmation requires advanced analytical methods, such as Raman spectroscopy or X-ray diffraction. ## Distinguishing from Similar Minerals Tatarinovite can be confused with other minerals from the ettringite group, such as ettringite itself or sturmanite, which form similarly shaped crystals. "Hand-specimen" differentiation is practically impossible without knowledge of the mineral association and analytical confirmation. It differs from them in chemical composition (presence of boron). ## Crystal Forms Tatarinovite crystallizes in the form of elongated, hexagonal prisms terminated by a pinacoid. The crystals are very small, usually not exceeding 0.5 mm in length, and form radial or chaotic aggregates and crystalline druses.

Geological environment

## Genesis Tatarinovite is a secondary mineral, forming in the oxidation zones of sulfide deposits. At its type locality (Norilsk), it formed as a result of low-temperature hydrothermal processes acting on basaltic volcanic rocks containing copper, nickel, and iron sulfides. ## Mineral Associations This mineral co-occurs with other rare secondary minerals. At the type locality, it was found in association with ettringite, gypsum, anhydrite, calcite, thaumasite, celestine, barite, goethite, and minerals from the serpentine group. ## Localities The only confirmed occurrence of tatarinovite worldwide is its type locality – the Mayak mine in the Talnakh area, within the Norilsk-Talnakh intrusion on the Putorana Plateau, Siberia, Russia.

Rarity

Very rare

For collectors

## Quality Criteria For collectors, the abundance and quality of crystals on the rock matrix are most important. Specimens with clearly formed, transparent, acicular crystals forming rich, radial aggregates are most valued. Contrast with the dark host rock also enhances the visual appeal of the specimen. ## Popular Localities All tatarinovite specimens available on the collector's market come from a single location worldwide – the Mayak mine in the Norilsk area of Russia.

Care and storage

## Cleaning Due to its extreme brittleness and softness, mechanical cleaning is not recommended. Specimens should only be cleaned with compressed air to remove dust. Contact with water, especially warm water, can damage or dissolve the crystals. ## What to Avoid Contact with water and any chemicals must be strictly avoided. The mineral is very sensitive to changes in temperature and humidity. It should not be heated or exposed to direct sunlight, which can lead to its dehydration and disintegration. ## Storage Tatarinovite specimens should be stored under stable conditions, preferably in closed, airtight containers (so-called "perky boxes") away from sources of heat, moisture, and vibrations. Due to its fragility, touching the crystals should be avoided.

External references

Sources

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