Pekovite

Chemical formula: SrB<sub>2</sub>Si<sub>2</sub>O<sub>8</sub>

Pekovite is a very rare strontium borosilicate, forming colorless, platy crystals with a vitreous luster.

## Characteristics Pekovite is an extremely rare mineral from the borosilicate group, chemically defined as strontium borosilicate. It occurs as very small, colorless, platy or bladed crystals, reaching sizes up to 0.3 x 0.1 x 0.02 mm. The crystals are transparent and exhibit a vitreous luster. Due to its extreme rarity and small crystal size, it is a mineral of purely scientific and collector's interest. ## Physical Properties This mineral has a hardness of approximately 6 on the Mohs scale. Its crystals are brittle, and the density calculated based on the chemical formula and unit cell parameters is 3.59 g/cm³. Pekovite's luster is vitreous, and its streak is white. It is transparent and does not exhibit pleochroism. ## History and Name The mineral is named in honor of Igor Viktorovich Pekov (born 1967), a Russian mineralogist and crystallographer from Moscow University, in recognition of his contributions to mineralogy, particularly in the study of alkaline pegmatite minerals. Pekovite was approved as a new mineral by the International Mineralogical Association (IMA) in 2003 (IMA2003-050). It was first described by A. P. Khomyakov and others in 2004. ## Uses Pekovite has no industrial applications. Its significance is limited to scientific research and advanced collections specializing in rare minerals or minerals from specific (so-called "systematic") localities.

Properties

Mohs hardness
6
Luster
Vitreous
Streak
White
Density
3.59
Cleavage
Good on {100}
Fracture
Uneven
Transparency
Transparent
Crystal system
Monoclinic

Diagnostic features

## Identification Amateur identification of pekovite is practically impossible. It requires advanced analytical techniques, such as X-ray diffraction (XRD) and chemical microanalysis (EDS/WDS) to confirm its composition (presence of strontium, boron, and silicon) and crystal structure. Visually, they are most often colorless, vitreous, platy microcrystals. ## Distinguishing from Similar Minerals Due to its appearance and occurrence, it can be confused with many other colorless silicate minerals found in similar environments, such as quartz, albite, or other rare minerals. Definitive differentiation is only possible using laboratory methods. ## Crystal Forms Pekovite crystallizes as thin, platy or bladed crystals, often flattened. It also forms aggregates composed of randomly oriented crystals.

Geological environment

## Genesis Pekovite forms under hydrothermal conditions, in highly alkalized pegmatites. At its discovery site (Koashva Mountain), it occurs in cavities within ultrabasic rocks (urtites) that have been altered by hydrothermal processes associated with pegmatitic intrusion. ## Mineral Associations This mineral coexists with other rare alkaline minerals. At the type locality, it was found in association with natrolite, villiaumite, lomonosovite, vuonnemite, zorite, bornemanite, sienkiewiczite, vitusite-(Ce), and kazakovite. ## Localities The only confirmed occurrence of pekovite in the world is its type locality: Koashva Mountain in the Khibiny Massif on the Kola Peninsula, Russia.

Rarity

Extremely rare

For collectors

## Quality Criteria The quality of a pekovite specimen is primarily determined by the presence of well-formed, identifiable (under a microscope) crystals on the rock matrix. Due to its microscopic size, clarity and color are not key factors. The most desirable specimens are those with rich crystal aggregates or in association with other rare minerals from this locality. ## Popular Localities The only source of pekovite specimens is the Khibiny Massif on the Kola Peninsula in Russia. All specimens available on the collector's market originate from this single location.

Care and storage

## Cleaning Due to its extreme rarity and small crystal size, pekovite specimens typically occur as microcrystals on a rock matrix. Cleaning, if absolutely necessary, should be limited to very gentle dust removal using a soft brush or a photographic air blower. Contact with water and any chemicals should be avoided. ## What to Avoid Avoid ultrasonic cleaners, chemical agents, acids, and bases. The crystals are brittle, so they should be protected from impacts, scratching, and vibrations. There is no data on its sensitivity to light or temperature, but standard caution is recommended. ## Storage Pekovite specimens should be stored under stable conditions, in sealed "micromount" boxes, to protect them from dust, moisture, and mechanical damage. It is best to keep them away from direct sunlight and heat sources.

Sources

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