Kopylovite

Chemical formula: K₂Ti₄+(Si₃O₉)

An extremely rare potassium titanium silicate from the benitoite group, discovered in kimberlite diatremes in Colorado.

## Characteristics Kopylovite is an extremely rare silicate mineral classified as a member of the benitoite group. Chemically, it is a potassium titanium cyclosilicate with the formula K₂Ti⁴⁺(Si₃O₉). The structure of minerals in this group is based on three-membered rings of silicate tetrahedra, with titanium and potassium cations located between them. Due to its extreme rarity, kopylovite usually occurs as microscopic crystals or fine grains that are not visible to the naked eye and require advanced analytical methods for correct identification. ## Physical properties The mineral crystallizes in the hexagonal crystal system, similar to other members of the benitoite group. Due to the microscopic size of known specimens and the fact that it is a relatively recently described mineral, many of its macroscopic physical properties are difficult to determine precisely without using highly specialized laboratory equipment. ## Colors and varieties No specific varieties of kopylovite have been described in mineralogical literature to date. It is a single, strictly defined mineral species. ## History and name Kopylovite was discovered and described based on research material from the United States. Its type locality is the Sloan No. 2 kimberlite diatreme, part of the Sloan diatreme complex in the State Line Kimberlite mining district, located in Larimer County, Colorado. ## Uses Due to its extreme rarity and microscopic size, kopylovite has absolutely no industrial or gemstone applications. It is solely an object of great scientific interest in the context of studies on ultramafic rock mineralogy and is sought after by highly specialized collectors of rare mineral species (so-called systematic collectors).

Properties

Crystal system: Hexagonal

Diagnostic features

## Identification Macroscopic identification of kopylovite in the field or in a collection is practically impossible. Advanced structural studies, primarily X-ray diffraction (XRD), and precise chemical composition analysis using an electron microprobe (EDS/WDS) are required for its definitive identification. ## Distinguishing from similar minerals This mineral is visually indistinguishable from other rare silicates occurring in ultramafic rocks. It requires distinction from other members of the benitoite group (such as benitoite itself or pabstite), which relies solely on demonstrating potassium dominance in the appropriate positions of the crystal structure. ## Crystal habits Kopylovite crystallizes in the hexagonal system. In nature, it usually forms very fine, microscopic grains and aggregates embedded in the matrix rock.

Geological environment

## Origin Kopylovite is a mineral associated with the specific environment of deep-seated ultramafic rocks. It forms in kimberlite diatremes, indicating its crystallization under specific chemical conditions and metasomatic processes occurring in these volcanic pipes. ## Mineral associations It occurs in kimberlitic rocks, co-occurring with minerals typical of this environment. It can be associated with olivine, pyroxenes, phlogopite, and other rare silicates and oxides characteristic of kimberlites. ## Localities The only confirmed and most important locality for this mineral in the world (the type locality) is the Sloan No. 2 kimberlite diatreme, located in the State Line district in Larimer County (Colorado, USA).

Rarity

Extremely rare

For collectors

## Quality criteria In the case of such extremely rare minerals, the primary and often only criterion of collector value is the confirmation of the species' presence on the specimen itself, usually supported by appropriate analytical documentation. Crystal size and development are of secondary importance. ## Market prices Due to the mineral's uniqueness, specimens of kopylovite extremely rarely appear on the open collector market, making it impossible to determine standard price ranges. ## Popular localities The only source of specimens for systematic collectors is the type locality in Colorado (Sloan No. 2 diatreme).

Care and storage

## Cleaning Specimens containing kopylovite should be handled with utmost care. Completely avoiding mechanical and chemical cleaning is recommended to avoid damaging the microscopic crystals. Gentle rinsing of the matrix rock with distilled water is the only acceptable method. ## What to avoid Contact with acids, strong bases, and ultrasonic cleaners must be strictly avoided. Vibrations and aggressive chemical environments can lead to irreversible destruction of the delicate research material. ## Storage Due to their very small size, specimens should be stored in standard micromount boxes. This provides protection against dust, moisture, and accidental mechanical damage during handling.

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External references

https://www.mindat.org/min-499398.html