Savelievaite

Chemical formula: Mg<sub>2</sub>Cr<sup>3+</sup>O<sub>2</sub>(BO<sub>3</sub>)

Savelievaite is an extremely rare magnesium chromium borate, forming microscopic, hexagonal crystals of an intense green color.

## Characteristics Savelievaite is a mineral from the borate group, characterized by a unique chemical composition containing magnesium and chromium. It occurs as extremely small, hexagonal, tabular crystals, rarely exceeding 0.2 mm. It forms rosette-like or radial aggregates. Its most characteristic feature is its intense, emerald-green color. ## Physical Properties Savelievaite crystals exhibit a vitreous luster. Due to the microscopic size of the crystals, many physical properties, such as hardness or density, have not been precisely determined. The mineral is transparent to translucent. ## Colors and Varieties This mineral occurs in a uniform, emerald-green color. No color or commercial varieties are known. ## History and Name Savelievaite was recognized as a new mineral by the IMA in 2017. Its name honors Lyudmila Nikolaevna Savelieva (born 1940), a Russian geologist specializing in the study of ultramafic rocks in the Polar Urals, where the mineral was discovered. It was described by a team of mineralogists, including I.O. Galuskina and E.V. Galuskin. ## Applications Due to its extreme rarity and microscopic size, savelievaite has no industrial applications. It is solely an object of scientific and collecting interest for specialized micromineral collectors.

Properties

Luster
Vitreous
Streak
Green
Cleavage
Perfect on {0001}
Fracture
Uneven
Transparency
Transparent to translucent
Crystal system
Hexagonal

Diagnostic features

## Identification In practice, the identification of savelievaite relies on chemical (EDS) and crystallographic (XRD) analysis. Visually, at the occurrence site, it can be suspected based on its characteristic emerald-green color, hexagonal crystal habit, and co-occurrence with other chromium and magnesium minerals in dolomitic marbles. ## Distinguishing from Similar Minerals It can be confused with other green chromium minerals found in similar environments, such as chromian dravite, uvarovite, or chromite. Differentiation requires advanced analytical methods. However, savelievaite is distinguished by its typical tabular, hexagonal habit and unique chemical composition (it is a borate). ## Crystal Forms It forms very small, thin, tabular crystals with a hexagonal outline. These crystals often combine into radial or rosette-like aggregates.

Geological environment

## Genesis Savelievaite forms as a result of metamorphic processes in a specific environment. It was discovered in calcite-dolomite marbles that underwent contact metamorphism in the contact zone with ophiolites (ultramafic rocks). ## Mineral Associations This mineral co-occurs with other minerals typical of such an environment, including calcite, dolomite, chromite, chromian dravite, chromian phlogopite, uvarovite, and also rare borates like karlite. ## Locations The only confirmed locality of savelievaite in the world (type locality) is the Centralnoye chromite deposit in the Rai-Iz massif in the Polar Urals, Russia.

Rarity

Extremely rare

For collectors

## Quality Criteria The quality of savelievaite specimens is primarily assessed based on the richness and size of crystal aggregates on the rock matrix. Specimens with clearly formed, rosette-like clusters of intense green color, contrasting well with white marble, are most valued. Due to the microscopic nature of the mineral, the quality of the specimen viewed under magnification is crucial. ## Popular Localities The only source of specimens is the type locality – the Centralnoye deposit in the Polar Urals, Russia. All specimens available on the collector's market originate from this single location.

Care and storage

## Cleaning Specimens should only be cleaned with compressed air to remove dust. Any contact with water, and especially with chemicals, is highly inadvisable due to the microscopic size and potential reactivity of the mineral. ## What to Avoid Avoid ultrasonic cleaners, all acids and bases, as well as sudden temperature changes. Do not touch the crystals, as they are extremely fragile and susceptible to mechanical damage. ## Storage Savelievaite specimens should be stored exclusively in specialized micromount boxes, protecting them from dust, moisture, and mechanical damage. Exposure to strong light is not recommended.

Sources

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