Chlorkyuygenite

Chemical formula: Ca₁₂Al₁₄O₃₂[(H₂O)₄Cl₂]

Chlorkyuygenite is an extremely rare mineral from the mayenite supergroup, known exclusively from meteorites and distinguished by its extraterrestrial origin.

## Characteristics Chlorkyuygenite is a hydrated calcium aluminate chloride, belonging to the mayenite supergroup. It forms very small, colorless or white crystals, rarely exceeding 50 micrometers in size. It typically occurs as single, well-formed grains or small, granular aggregates. Its crystals most often take the form of rhombic dodecahedra. ## Physical Properties This mineral has a Mohs hardness of 5.5. It has a vitreous luster and is transparent to translucent. Its calculated density is approximately 2.75 g/cm³. It is brittle and exhibits a conchoidal fracture. ## Colors and Varieties Chlorkyuygenite is usually colorless, sometimes white. No colored or commercial varieties are known. ## History and Name The mineral was officially recognized by the IMA in 2011. Its name refers to its chemical composition (presence of chlorine) and its discovery location – it comes from the word "kyuygen," which in the Even language means "fireball" (a metaphor for a meteorite). It was discovered in the Khatyrka chondrite meteorite, found in Koryak-Kamchatka, Russia. ## Applications Due to its extreme rarity and microscopic size, chlorkyuygenite has no practical applications. It is solely an object of scientific research and interest for specialized collectors of extraterrestrial minerals.

Properties

Mohs hardness: 5.5
Luster: Vitreous
Streak: White
Density: 2.75
Cleavage: None
Fracture: Conchoidal
Transparency: Transparent to translucent
Crystal system: Isometric

Diagnostic features

## Identification Amateur identification of chlorkyuygenite is practically impossible. A key diagnostic feature is its unique occurrence environment – inclusions within a chondrite meteorite. Identification relies on microscopic analysis and chemical composition studies (e.g., by EDS) and crystal structure (XRD). It occurs as very small, colorless, isometric crystals. ## Distinguishing from Similar Minerals Chlorkyuygenite is visually indistinguishable from other minerals of the mayenite supergroup, such as chlormayenite or mayenite. The differences between them lie in subtle changes in the proportions of chlorine, water, and other ions in the crystal structure, which requires advanced instrumental analysis. From other colorless minerals (e.g., grossular, spinel), it is primarily distinguished by its paragenesis and extraterrestrial origin. ## Crystal Forms It crystallizes in the isometric system, most often forming crystals in the shape of a rhombic dodecahedron. It occurs as single, isolated grains or in small, granular aggregates within the parent rock (meteorite).

Geological environment

## Genesis Chlorkyuygenite is a mineral of extraterrestrial origin. It formed as a result of metamorphic and metasomatic processes occurring under high-temperature and low-pressure conditions. Its formation is associated with the transformation of calcium- and aluminum-rich inclusions (CAIs - Calcium-Aluminium-rich Inclusions) within a CV3 type carbonaceous chondrite. ## Mineral Associations This mineral occurs in association with other rare meteoritic minerals. Its main associations include: diopside, andradite, grossular, kirschsteinite, forsterite, spinel, and other minerals from the mayenite supergroup, such as chlormayenite. ## Localities The only confirmed locality of chlorkyuygenite in the world is the Khatyrka meteorite, found in 2011 in the Koryak Mountains (Koryak-Kamchatka, Far Eastern Federal District, Russia).

Rarity

Extremely rare

For collectors

## Quality Criteria The quality of chlorkyuygenite specimens is assessed based on several criteria. The most important is the abundance of the mineral on the matrix – the more visible microcrystals, the more valuable the specimen. The degree of crystal development and sharpness of edges, as well as the presence of interesting associated minerals, are also important. Due to their microscopic nature, specimens are evaluated under magnification. ## Popular Localities The only source of specimens of this mineral is the Khatyrka meteorite from Russia. Material from this find is extremely rare and primarily available in institutional and research collections.

Care and storage

## Cleaning Chlorkyuygenite specimens, being fragments of a meteorite, are extremely delicate and valuable. Cleaning should be kept to an absolute minimum. Only a soft brush or a photographic air blower should be used to remove dust. Contact with water and any chemical agents should be avoided. ## What to Avoid The mineral is sensitive to acids. Avoid sudden temperature changes, vibrations, and ultrasonic cleaning, which could damage microscopic crystals or the entire parent sample. ## Storage Specimens should be stored under stable conditions, in a sealed "micromount" box, protecting them from dust, moisture, and direct sunlight. It is best to store them in their original container with a label documenting their origin.

Sources

IMA Mineral List (CNMNC)