Kuratite
Chemical formula: Ca<sub>2</sub>(Fe<sup>2+</sup><sub>5</sub>Ti<sup>4+</sup>)O<sub>2</sub>[Si<sub>4</sub>Al<sub>2</sub>O<sub>18</sub>]
Kuratite is an extremely rare mineral from the osumilite group, found exclusively in a single meteorite.
Properties
- Mohs hardness
- 5-6
- Luster
- Vitreous
- Streak
- White
- Density
- 3.43
- Cleavage
- None
- Fracture
- Uneven
- Transparency
- Transparent
- Crystal system
- Hexagonal
Diagnostic features
## Identification Identification of kuratite is possible only through advanced laboratory techniques, such as electron microprobe analysis (EMPA) for chemical composition and electron backscatter diffraction (EBSD) for crystal structure determination. Its colorless appearance in transmitted light and co-occurrence with other rare minerals in the NWA 470 meteorite are key indicators. ## Distinguishing from Similar Minerals Due to its unique chemical composition, especially the simultaneous presence of calcium, iron, titanium, silicon, and aluminum in specific proportions, it is easily distinguishable from other minerals by chemical analysis. Structurally, it belongs to the osumilite group, but its chemical composition is unique. ## Crystal Forms Only anhedral (irregular) inclusion grains within other minerals have been observed.
Geological environment
## Genesis Kuratite formed under high-temperature and low-pressure conditions, characteristic of certain processes occurring in meteorite parent bodies. It is believed to have crystallized from an aluminum- and calcium-rich fluid or melt within a CV3 carbonaceous chondrite. Its formation is associated with sodic metasomatism, which led to the formation of aluminum-rich inclusions (CAIs - Calcium-Aluminum-rich Inclusions). ## Mineral Associations This mineral occurs in close association with hercynite, anorthite, nepheline, sodalite, as well as rarer minerals such as dmitryivanovite, grossmanite, hibonite, and perovskite. All these minerals form complex aggregates within inclusions in the meteorite. ## Localities The only confirmed locality of kuratite in the world is the NWA 470 meteorite (Northwest Africa 470), a carbonaceous chondrite found in 2001 in Morocco. This is the type locality for this mineral.
Rarity
Extremely rare
For collectors
## Quality Criteria Kuratite is not a mineral available on the collector's market. Its value is purely scientific. The only form in which it can be possessed is a fragment of the NWA 470 meteorite in which it was identified. The value of such a specimen is determined by its provenance, size, and scientific significance, not by the visual characteristics of kuratite itself, which is invisible to the naked eye. ## Market Prices No data available. The mineral is not traded.
Care and storage
## Cleaning Due to its extreme rarity and microscopic nature, kuratite specimens (embedded in the meteorite matrix) should not be subjected to any cleaning treatments. Any attempt at cleaning risks irreversible loss or damage to the scientific material. ## What to Avoid Avoid all chemicals, ultrasonics, temperature changes, and moisture. The parent specimen (meteorite) should be protected from conditions conducive to oxidation. ## Storage Store exclusively under stable laboratory or museum conditions, preferably in a sealed container with a desiccant, in a dark and dry place. All manipulations should be performed only by specialized personnel under laboratory conditions.