Pavlovskyite

Chemical formula: Ca₈(SiO₄)₂(Si₃O₁₀)

Pavlovskyite is a very rare calcium silicate, forming colorless, tabular crystals with a vitreous luster.

## Characteristics Pavlovskyite is an extremely rare mineral from the silicate group, chemically a complex calcium silicate. It occurs as very small, colorless, tabular crystals, usually not exceeding 0.2 mm in length. These crystals are transparent and characterized by a vitreous luster. ## Physical Properties This mineral has a hardness of approximately 5 on the Mohs scale. Its density, calculated from crystallographic data, is 2.95 g/cm³. Pavlovskyite crystals exhibit perfect cleavage in one direction. ## History and Name The mineral's name honors Evgeny Vladimirovich Pavlovsky (1901-1989), a Russian geologist specializing in tectonics, who studied the Baikal region. Pavlovskyite was first described in 2011 after its discovery in a carbonate-silicate xenolith within volcanic rocks of the Sivian caldera in the Bodaybo district, Irkutsk Oblast, Russia.

Properties

Mohs hardness
6-6.5
Color
White
Luster
Vitreous
Streak
White
Density
2.97
Cleavage
Uneven on {001}
Fracture
Irregular/Uneven
Transparency
Transparent
Crystal system
Orthorhombic

Diagnostic features

## Identification Identification of pavlovskyite is possible only through advanced analytical methods, such as X-ray diffraction (XRD) and chemical analysis (EDS/WDS). Visual identification is impossible due to its small size and lack of characteristic macroscopic features. ## Differentiation from similar minerals It can be confused with many other colorless silicates found in similar environments, such as wollastonite, diopside, or other rare calcium silicates. Differentiation requires specialized laboratory equipment. ## Crystal forms It forms flattened, tabular crystals with a hexagonal outline. Crystals are typically very small, with dimensions not exceeding 0.2 x 0.1 x 0.01 mm.

Geological environment

## Genesis Pavlovskyite forms under conditions of high-temperature contact metamorphism. It was found in carbonate-silicate xenoliths that were entrained and transformed by hot trachyte magma. ## Mineral associations It coexists with minerals such as bultfonteinite, cuspidine, larnite, rondorfite, jurgensonite, as well as members of the ettringite group. ## Localities The only confirmed occurrence of pavlovskyite in the world (type locality) is the Sivian volcanic caldera in the Vacha River basin, Bodaybo district, Irkutsk Oblast, Siberia, Russia.

Rarity

Extremely rare

For collectors

## Quality criteria As a "micromount" type mineral, its collector value depends on the size and quality of the crystals, and above all, on their association with other rare minerals on the rock matrix. Any specimen with well-formed crystals, even microscopic ones, is considered unique. ## Popular localities Specimens originate exclusively from the type locality in Russia, making them extremely difficult to acquire on the collector's market.

Care and storage

## Cleaning Due to its extreme rarity and small crystal size, mechanical cleaning is not recommended. If necessary, compressed air can be used to remove dust. Avoid contact with water and chemicals. ## What to avoid Avoid all acids, solvents, and ultrasonics. The mineral is sensitive to shocks and temperature changes. It should not be exposed to direct sunlight. ## Storage Pavlovskyite specimens should be stored exclusively in specialized, sealed "micromount" boxes, protecting them from dust, moisture, and mechanical damage. Store under stable temperature conditions.

External references

Sources

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