Nataliakulikite

Chemical formula: Ca₄Ti₄+₂(Fe₃+,Fe₂+)(Si,Fe₃+,Al)O₁₁

Nataliakulikite is an extremely rare mineral from the perovskite group, found in metamorphosed calcareous-silicate rocks in the Middle East region.

## Characteristics Nataliakulikite is an oxide mineral belonging to the perovskite supergroup. It occurs as very fine, subhedral (partially developed) grains not exceeding 200 micrometers in size, usually forming aggregates. It is opaque and has a black color with a metallic luster. ## Physical Properties Due to the microscopic size of the crystals, most physical properties, such as hardness, density, or cleavage, have not been precisely determined. The luster is metallic, and the streak is black. ## History and Name The mineral was officially recognized by the International Mineralogical Association (IMA) in 2013. Its name honors Natalia Kulik (born 1933), a Russian geologist and petrologist, for her contribution to the study of rocks from the Hatrurim Formation, where this mineral was discovered. ## Applications Nataliakulikite has no industrial applications. Its significance is purely scientific and collectible, as an extremely rare member of the perovskite supergroup.

Properties

Luster: Metallic
Streak: Black
Cleavage: None
Fracture: Uneven
Transparency: Opaque
Crystal system: Tetragonal

Diagnostic features

## Identification Identification of nataliakulikite is impossible without advanced analytical techniques. This requires chemical analysis (e.g., using an electron microprobe - EDS/WDS) and structural studies (X-ray diffraction - XRD). Visually, it is simply a black, metallic mineral occurring as very fine grains. ## Distinguishing from similar minerals It can be confused with other black, metallic oxide minerals found in similar parageneses, such as magnetite, chromite, or other minerals from the perovskite group. Definitive differentiation is only possible based on chemical composition, where the presence of calcium, titanium, and iron in specific proportions is crucial. ## Crystal forms Nataliakulikite forms very small, subhedral grains that combine into irregular aggregates. Well-formed, single crystals have not been observed.

Geological environment

## Genesis Nataliakulikite forms under conditions of high-temperature, low-pressure contact metamorphism. It develops in calcareous-silicate rocks (skarns) that originated from the combustion and pyrometamorphism of bituminous marls, as in the case of the Hatrurim Formation. ## Mineral associations This mineral coexists with other rare minerals typical of the Hatrurim Formation, such as larnite, brownmillerite, jasmundite, ye'elimite, as well as gehlenite, rankinite, wollastonite, and members of the spinel group. ## Localities The only confirmed occurrence (type locality) of nataliakulikite is the Hatrurim Formation near Har Parsa in the Negev Desert, Israel. This is a unique geological environment known for the occurrence of many rare minerals formed by pyrometamorphic processes.

Rarity

Extremely rare

For collectors

## Quality criteria As a microscopic mineral, the collectible value of a nataliakulikite specimen primarily depends on the confirmation of its identity by a reputable laboratory. The most valuable specimens are those where nataliakulikite grains are as "large" as possible (though still microscopic) and abundant, and also well-documented in terms of association with other rare minerals from that locality.

Care and storage

## Cleaning Specimens containing nataliakulikite, due to the microscopic nature of the grains and their embedding in the host rock, generally do not require and should not undergo cleaning. Dust removal should be done using a soft brush or a photographic air blower. ## What to avoid Avoid contact with chemicals, especially acids, which can damage both the mineral itself and the host rock. Ultrasonic cleaners and steam cleaning should also be avoided. ## Storage Specimens should be stored in stable conditions, away from dust, humidity, and extreme temperature changes. It is best to keep them in sealed "micromount" boxes to protect the delicate, microscopic crystals from mechanical damage.

Sources

IMA Mineral List (CNMNC)