Kabalovite

Chemical formula: Fe₂+₃Fe₃+₄(PO₄)₆

Kabalovite is a very rare iron phosphate, forming black, metallic-lustered grains and aggregates in iron meteorites.

## Characteristics Kabalovite is a mineral from the phosphate group, composed of iron in the divalent and trivalent oxidation states. It occurs as very fine, irregular grains up to 200 micrometers in size, which form aggregates. Its black color and metallic luster are characteristic visual features. ## Physical Properties This mineral is opaque. Due to the microscopic size of the grains, precise determination of hardness and density has not been possible; however, the density calculated based on the formula and crystallographic data is 3.86 g/cm³. ## Colors and Varieties Kabalovite is black. No varieties have been distinguished. ## History and Name The mineral's name honors the Russian crystallographer Yuri Konstantinovich Kabalov (born 1939) from Moscow State University, in recognition of his contributions to the study of mineral crystal structures. Kabalovite was approved as a new mineral by the International Mineralogical Association (IMA) in 2016 (IMA2016-061). It was described based on material found in the Onello iron meteorite, discovered in 1998 in Russia.

Properties

Luster: Metallic
Streak: Black
Density: 3.86
Cleavage: None
Fracture: Uneven
Transparency: Opaque
Crystal system: Monoclinic

Diagnostic features

## Identification Identification of kabalovite is possible only through advanced laboratory methods, such as backscattered electron (BSE) spectroscopy in an electron microscope, where it distinguishes itself by its gray tone from other co-occurring phosphates, as well as chemical analysis (EDS/WDS) and X-ray diffraction. Visual identification is impossible. ## Distinguishing from Similar Minerals Kabalovite occurs in paragenesis with other iron phosphates, such as graftonite, saterlite, and galileiite. Differentiation from these requires analysis of chemical composition and crystal structure. In BSE images, kabalovite is darker than saterlite but lighter than graftonite. ## Crystal Forms This mineral forms exclusively anhedral (lacking well-formed faces) grains and irregular aggregates of grains.

Geological environment

## Genesis Kabalovite is a mineral of extraterrestrial origin. It forms as a result of shock metamorphism and oxidation processes within iron meteorites belonging to the IAB group. It forms in silicate-phosphate nodules within the metallic matrix (kamacite and taenite). ## Mineral Associations This mineral co-occurs with other phosphates, such as graftonite-(Fe), saterlite, galileiite, as well as chromite, troilite, schreibersite, graphite, and silicates from the olivine and pyroxene groups. ## Localities The only confirmed locality of kabalovite in the world is the Onello iron meteorite, found in the Onello River basin in Yakutia (Sakha Republic), Russia.

Rarity

Extremely rare

For collectors

## Quality Criteria Kabalovite does not occur in the form of collector's specimens in the common sense. Its value is purely scientific. The only form in which it can be possessed is a fragment of the Onello meteorite in which this mineral has been identified. The value of such a specimen is determined by its scientific significance and provenance, rather than the visual characteristics of kabalovite itself, which is invisible to the naked eye.

Care and storage

## Cleaning Due to its extreme rarity and occurrence as microscopic grains embedded in the meteorite matrix, kabalovite specimens are not subject to cleaning in the traditional sense. Any cleaning attempts should be undertaken exclusively in laboratory conditions by specialists. ## What to Avoid Contact with chemicals, acids, and strong bases, which can react with phosphates, should be avoided. Abrasion and ultrasonics, which could damage the delicate grains and the surrounding matrix, should also be avoided. ## Storage Specimens containing kabalovite should be stored in stable conditions, in a specialized collector's box, away from moisture, dust, and sudden temperature changes, to protect both the mineral itself and the meteorite matrix.

Sources

IMA Mineral List (CNMNC)