Grokhovskyite

Chemical formula: CuCrS<sub>2</sub>

Grokhovskyite is a rare copper and chromium sulfide, found exclusively in iron meteorites, forming tiny, hexagonal crystals.

## Characteristics Grokhovskyite is a copper and chromium sulfide, occurring as extremely small, hexagonal, tabular crystals, usually not exceeding 100 micrometers in size. It is observed as inclusions in troilite, often accompanied by other rare minerals. Its crystals have a metallic luster and are opaque. ## Physical Properties This mineral is characterized by a metallic luster and a black color with a brownish tint in reflected light. It is opaque. Due to the microscopic size of the crystals, precise determination of hardness and density is difficult; however, the density calculated based on the formula and unit cell parameters is 4.43 g/cm³. ## History and Name Grokhovskyite was officially recognized as a new mineral by the International Mineralogical Association (IMA) in 2019 (IMA2019-023). Its name honors Victor Grokhovsky, a Russian scientist from Ural Federal University, for his contribution to meteorite research. The mineral was discovered and described by a team of scientists led by Grigory A. Yudin. ## Uses Grokhovskyite has no industrial applications. Its significance is purely scientific and collectible, as an extremely rare component of meteorites, providing information about the formation processes of celestial bodies.

Properties

Luster
Metallic
Streak
Black
Density
4.43
Cleavage
Perfect on {0001}
Transparency
Opaque
Crystal system
Hexagonal

Diagnostic features

## Identification Identification of grokhovskyite is possible only through advanced laboratory methods, such as scanning electron microscopy (SEM) with chemical composition analysis (EDS) and electron backscatter diffraction (EBSD). In reflected light under a polarizing microscope, it is dark gray with a brownish tint and exhibits weak pleochroism. ## Distinguishing from Similar Minerals Due to its unique chemical composition (combination of Cu, Cr, and S) and occurrence in a specific environment, it is difficult to confuse with other minerals after chemical analysis. Visually, without analysis, it is indistinguishable from other tiny, opaque inclusions in meteorites. ## Crystal Forms It forms very small, hexagonal, tabular crystals, which occur as single flakes or their aggregates within larger troilite crystals.

Geological environment

## Genesis Grokhovskyite is an extraterrestrial mineral. It forms in iron meteorites, in this case, in an ataxite of the IVB group, as a result of processes occurring within the parent celestial body. It crystallizes in troilite-daubréelite nodules, probably in the late stages of the formation of these aggregates. ## Mineral Associations This mineral co-occurs with troilite, daubréelite, chromite, kamacite, taenite, and another rare mineral - tiglite. ## Localities The only confirmed locality of grokhovskyite in the world (type locality) is the Uakit iron meteorite, found in 2016 in the Baunt district, Buryatia, Russia.

Rarity

Extremely rare

For collectors

## Quality Criteria The quality of a grokhovskyite specimen is identical to the quality of the Uakit meteorite fragment in which it is found. Since the mineral is microscopic, its collectible value is not based on its visual characteristics, but on the fact of its presence, scientifically confirmed. The most valuable specimens are those with an attached certificate and analytical documentation confirming the identification of grokhovskyite. ## Popular Localities The only source of specimens is the Uakit meteorite from Russia. Fragments of this meteorite, containing confirmed grokhovskyite, are highly sought after by specialized mineral and meteorite collectors.

Care and storage

## Cleaning Specimens containing grokhovskyite, which are fragments of meteorites, should not be wet-cleaned. Any contaminants, such as dust, should be removed only with a soft brush or compressed air from a safe distance. ## What to Avoid Absolute avoidance of contact with water, chemicals, acids, and cleaning agents is essential, as they can react with associated minerals (mainly troilite and iron) and lead to irreversible damage to the specimen. Iron meteorites are susceptible to rusting in humid environments. ## Storage Specimens with grokhovskyite must be stored in conditions of controlled, low humidity, preferably in airtight containers (e.g., "membrane boxes") or in display cases with a desiccant (e.g., silica gel). Protect from dust and direct contact with hands.

Sources

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