Kopernikite

Chemical formula: K(Ti₄+₇Cr₃+)O₁₆

Kopernikite is an extremely rare mineral of the priderite group, discovered in the Polish Morasko meteorite, occurring exclusively in the form of microscopic grains.

## Characteristics Kopernikite is a rare potassium, titanium, and chromium oxide belonging to the priderite group. It occurs exclusively in the form of microscopic grains inside silicate inclusions in iron meteorites. In mass, it assumes a dark green color, whereas in thin sections it becomes yellow-green. Due to its microscopic size, it does not form macroscopic specimens, and its identification requires advanced analytical studies. ## Physical properties This mineral crystallizes in the tetragonal system. Its Mohs hardness is 5.5, and its density was determined to be 3.92 g/cm³. The streak of kopernikite has a light green shade. Due to its occurrence in the form of microcrystals, many macroscopic features are difficult to observe directly. ## Colors and varieties Kopernikite has no known varieties. Its color is strictly related to the grain thickness - from dark green in thicker, massive fragments to yellow-green in very thin layers. ## History and name The mineral was first described based on studies of the Morasko meteorite, found in the area of present-day Poznań in Poland. Its name honors Nicolaus Copernicus, an outstanding Polish astronomer. It was officially approved by the International Mineralogical Association (IMA).

Properties

Mohs hardness: 5.5-0
Color: dark-green in massive grains to yellow-green in thin grains,
Streak: light-green
Density: 3.92
Crystal system: Tetragonal

Diagnostic features

## Identification Identification of kopernikite in amateur or field conditions is impossible. This mineral is identified exclusively in laboratory studies, using an electron microprobe or X-ray diffraction within polished sections of meteorites. ## Distinguishing from similar minerals Chemically and structurally, it is related to other minerals of the priderite group. In meteoritic inclusions, it can co-occur with kosmochlor, which also contains chromium and has a green color. Distinguishing these minerals requires precise chemical composition analysis. ## Crystal habits It forms microscopic, massive grains. No well-formed, macroscopic crystals have been observed so far.

Geological environment

## Genesis Kopernikite is a mineral of extraterrestrial origin. It forms under specific reducing conditions inside the parent bodies of iron meteorites, crystallizing within silicate inclusions. ## Mineral associations It occurs in close association with other meteoritic minerals. In the type locality, it is accompanied by pyroxenes, olivine, troilite, graphite, schreibersite, and kosmochlor. ## Localities The type locality is the Morasko meteorite, found within the borders of present-day Poznań (Greater Poland Voivodeship, Poland).

Rarity

Extremely rare

For collectors

## Quality criteria Kopernikite does not occur as an independent collectible mineral. Its value relies entirely on its presence in documented, scientifically studied fragments of the Morasko meteorite. For collectors, the mere fact of owning a polished meteorite slice with silicate inclusions that could potentially contain microscopic grains of this mineral is what matters. ## Popular localities The only source of specimens containing this mineral is the Morasko meteorite fall in Poland.

Care and storage

## Cleaning Kopernikite occurs exclusively as a microscopic component of iron meteorites. Care therefore applies to whole meteorite specimens, which should be dry-cleaned only, using a soft brush or compressed air. ## What to avoid Moisture, water, and any chemicals must be strictly avoided. The iron matrix of the meteorite (composed mainly of kamacite and taenite) in which the mineral is embedded is highly susceptible to oxidation and rusting. ## Storage Meteorite specimens containing kopernikite should be stored in a dry environment, preferably in airtight containers with added silica gel to absorb moisture. Maintaining a constant temperature and low air humidity is recommended.

Browse minerals in the shop

External references

https://www.mindat.org/min-499374.html