Nazarchukite
Chemical formula: Ca<sub>2</sub>Ni<sup>2+</sup>Fe<sup>3+</sup><sub>2</sub>(PO<sub>4</sub>)<sub>4</sub>
Nazarchukite is an extremely rare calcium, nickel, and iron phosphate, forming microscopic, brown crystals at its only known locality in Israel.
Description
## Characteristics Nazarchukite is a very rare mineral from the howardevansite group, belonging to the phosphate class. Chemically, it is a hydrated calcium, nickel, and iron phosphate. It forms very small, platy or lamellar crystals that combine into rosette-like aggregates up to 0.5 mm in size. Individual crystals rarely exceed 150 micrometers. Due to its microscopic size, it is a mineral primarily of interest to scientists and specialized micromineral collectors. ## Physical Properties The mineral is characterized by a vitreous luster and is translucent. Its hardness has not been directly measured but is calculated to be approximately 4.5 on the Mohs scale based on microhardness tests. The measured density is 3.73 g/cm³. ## Colors and Varieties Nazarchukite occurs in a uniform color, from brown to dark brown. No color varieties or commercial forms are known. ## History and Name The mineral was officially recognized by the International Mineralogical Association (IMA) in 2022 (IMA 2022-076). Its name honors Zinaida Vasylivna Nazarchuk (born 1956), a Ukrainian mineralogist and crystallographer from Ivan Franko National University of Lviv, in recognition of her contributions to mineralogical research.
Diagnostic features
## Identification Amateur identification of nazarchukite is impossible. Its recognition requires advanced laboratory techniques, such as chemical composition analysis (EDS) and X-ray diffraction (XRD). A key clue is its occurrence in the specific geological environment of the Hatrurim Formation. ## Distinguishing from Similar Minerals It can be confused with other fine-grained, brown phosphates or oxides found in the same environment. Certain differentiation from gurimite, magnesioferrite, or hematite is only possible based on instrumental analysis. ## Crystal Forms It forms tabular, very thin crystals with a hexagonal outline, which aggregate into rosette-like forms or small, flattened spheres.
Geological environment
## Genesis Nazarchukite forms under unique conditions of pyrometamorphism – a process of rock alteration under very high temperature and low pressure. It is a product of natural combustion and melting of sedimentary rocks within the Hatrurim Formation. ## Mineral Associations This mineral occurs in association with other rare minerals typical of the Hatrurim Formation, such as gurimite, periclase, magnesioferrite, hematite, fluorapatite, and nickeline. ## Localities The only confirmed locality of nazarchukite in the world is its type locality: Wadi Halamish in the southern Negev Desert in Israel, within the rocks of the Hatrurim Formation.
Rarity
Extremely rare
Collector aspects
## Quality Criteria As a microscopic mineral, its collector value is determined by the quality of the specimen under the microscope. Specimens with well-formed, sharp crystals forming aesthetic aggregates are most desirable. The presence of interesting associated minerals on the same rock matrix is also important. ## Popular Localities The only source of specimens is the type locality in Israel. Material from this location is extremely difficult to obtain and primarily goes to scientific institutions and highly specialized collectors.
Care and storage
## Cleaning Due to the extreme rarity and microscopic size of specimens, any attempts at mechanical or chemical cleaning are discouraged. Specimens should be treated solely as scientific or collectible objects for observation under a microscope. ## What to Avoid Contact with all chemicals, especially acids, which can destroy the mineral, must be strictly avoided. Specimens are very fragile and sensitive to shocks and abrasion. They should be protected from dust and moisture. ## Storage It is recommended to store nazarchukite only in specialized micromount boxes, which protect the specimen from physical damage and contamination. A label with the exact locality is crucial.