Matyhite
Chemical formula: Ca<sub>9</sub>(Ca<sub>0.5</sub>☐<sub>0.5</sub>)Fe<sup>2+</sup>(PO<sub>4</sub>)<sub>7</sub>
An extremely rare calcium iron phosphate from the merrillite group, forming microscopic, colorless grains in pyrometamorphic rocks.
Description
## Characteristics Matyhite is a phosphate mineral belonging to the merrillite group. It occurs as very small, anhedral grains, rarely exceeding 0.2 mm in size. It is colorless or pale yellow, with a vitreous luster. It is usually transparent. Due to the microscopic size of the specimens, its visual characteristics are difficult to observe without specialized equipment. ## Physical Properties Its Mohs hardness is 5. It does not exhibit cleavage. The density calculated from the chemical formula and unit cell parameters is approximately 3.23 g/cm³. The mineral is brittle. ## Colors and Varieties Observed colors are colorless and pale yellow. No color or commercial varieties have been distinguished. ## History and Name Matyhite was officially recognized as a new mineral by the International Mineralogical Association (IMA) in 2015. Its name comes from its discovery locality – Matyha Hill (Hebrew: מתיא) within the Hatrurim Formation in the Negev Desert, Israel. ## Applications Due to its extreme rarity and microscopic size, matyhite has no industrial applications. It is solely an object of scientific interest and a valuable acquisition for specialized collectors of rare minerals.
Diagnostic features
## Identification Identification of matyhite based on visual characteristics is impossible. A key clue is its origin from a unique geological environment – the pyrometamorphic rocks of the Hatrurim Formation in Israel. Definitive identification requires advanced analytical methods, such as X-ray microanalysis (EDS/WDS) to confirm the chemical composition and X-ray diffraction (XRD) to determine the crystal structure. ## Distinguishing from Similar Minerals It can be confused with other colorless, microscopic minerals found in the same environment, such as fluorapatite or other rare phosphates. Without specialized laboratory tests, distinguishing it from these minerals is impossible. ## Crystal Forms Matyhite forms exclusively irregular, anhedral grains embedded in the host rock. No well-formed crystals have been observed.
Geological environment
## Genesis Matyhite forms under rare and specific pyrometamorphic conditions. It is a product of high-temperature transformations of sedimentary rocks that occur in the Hatrurim Formation. It forms in small veins cutting through rocks referred to as paralavas. ## Mineral Associations This mineral coexists with other minerals typical of the Hatrurim Formation. It is most often accompanied by hematite, magnetite, fluorapatite, as well as other, often yet undescribed, rare calcium and iron phosphates. ## Localities The only known and confirmed locality of matyhite in the world is its type locality: Matyha Hill, Hatrurim Formation, Negev Desert, Israel.
Rarity
Extremely rare
Collector aspects
## Quality Criteria In the case of such a rare micromineral, collectible value is not assessed based on typical aesthetic criteria. The most important factors are: the richness of the specimen (quantity and concentration of matyhite grains on the host rock), the size of the grains (even if they are fractions of a millimeter), and a well-documented association with other rare minerals from this locality. ## Popular Localities Specimens come exclusively from one place in the world – Matyha Hill in Israel. It is an extremely difficult mineral to acquire, available only in specialized collecting circles and scientific institutions.
Care and storage
## Cleaning Matyhite specimens are typically microminerals embedded in the host rock. Cleaning should be limited to gently removing dust with compressed air. Contact with water and any chemicals that could damage both the mineral and the associated rock should be avoided. ## What to Avoid Ultrasonic cleaners should be absolutely avoided, as they can cause microscopic grains to detach from the substrate. The mineral should be protected from high temperatures, sudden thermal changes, and all chemicals. Due to its brittleness, specimens are very sensitive to impacts and vibrations. ## Storage The safest storage method is to place the specimen in a specialized "micromount" box, with an appropriate label. This protects the mineral from dust, mechanical damage, and allows for safe observation under a microscope.