Ilyukhinite

Chemical formula: (H<sub>3</sub>O,Na)<sub>14</sub>Ca<sub>6</sub>Mn<sup>2+</sup><sub>2</sub>Zr<sup>4+</sup><sub>3</sub>Si<sub>26</sub>O<sub>72</sub>(OH)<sub>2</sub>·3H<sub>2</sub>O

Ilyukhinite is a very rare mineral from the eudialyte group, distinguished by its complex chemical composition and occurrence as fine grains.

## Characteristics Ilyukhinite is a complex cyclosilicate belonging to the eudialyte group. It typically forms very small, anhedral (irregularly shaped) grains up to 0.3 mm in size, occurring in association with other minerals. Due to the small size of the crystals, its visual features are difficult to observe with the naked eye. In transmitted light, it is colorless to pale yellow. ## Physical Properties This mineral is characterized by a vitreous luster and a white streak. It is brittle, and its Mohs hardness is approximately 5. The density calculated from crystallographic data is 2.96 g/cm³. ## Colors and Varieties Observed colors are pale yellow or colorless. No varieties of this mineral have been distinguished. ## History and Name Ilyukhinite was named in honor of Vladimir Valentinovich Ilyukhin (1934–1982), a Russian crystallographer who made significant contributions to the study of silicate structures, including minerals of the eudialyte group. It was approved as a new mineral by the International Mineralogical Association (IMA) in 2015 (IMA2015-064). The type locality is Mount Kedykverpakhk in the Lovozero Massif on the Kola Peninsula, Russia. ## Uses Due to its extreme rarity and microscopic size, ilyukhinite has no commercial or industrial applications. It is solely an object of scientific and collecting interest for specialized micromount mineral collectors.

Properties

Mohs hardness
5
Luster
Vitreous
Streak
White
Density
2.96
Cleavage
None
Fracture
Uneven
Transparency
Transparent to translucent
Crystal system
Trigonal

Diagnostic features

## Identification Identification of ilyukhinite is impossible without advanced analytical techniques. It requires chemical analysis (e.g., using an electron microprobe) and X-ray diffraction (XRD) methods to confirm its unique crystal structure and composition. Visually, on a micro scale, it can be suspected based on the mineral association in samples from the Lovozero Massif. ## Distinguishing from Similar Minerals Ilyukhinite is one of many minerals from the eudialyte group, which are very similar visually. Distinguishing it from other members of this group, such as eudialyte, kentbrooksite, or oneillite, is only possible through detailed laboratory studies. All these minerals form similar granular aggregates in alkaline pegmatites. ## Crystal Forms This mineral occurs as anhedral, i.e., irregular, grains not exceeding 0.3 mm in size. It has not been observed in the form of well-developed crystals.

Geological environment

## Genesis Ilyukhinite forms in highly differentiated, peralkaline agpaitic pegmatites. It is a mineral of the late-stage hydrothermal crystallization in these specific geological environments. Its typical locality is a pegmatite within a nepheline syenite massif. ## Mineral Associations This mineral coexists with other rare minerals typical of the Lovozero Massif pegmatites. It is most commonly associated with: eudialyte, arfvedsonite, aegirine, nepheline, microcline, lorenzenite, lomonosovite, villiaumite, and manganoneptunite. ## Localities The only confirmed occurrence of ilyukhinite in the world is its type locality: Mount Kedykverpakhk in the Lovozero Massif, on the Kola Peninsula, Murmansk Oblast, Russia.

Rarity

Extremely rare

For collectors

## Quality Criteria As a micromount mineral, the collector's value of ilyukhinite is determined by the quality of the entire specimen. The most desirable specimens are those where ilyukhinite grains, though small, are clearly visible and abundant on the matrix. The presence of rare associated minerals is also crucial, as it enhances the scientific and aesthetic value of the specimen. Confirmation of identification by an analytical laboratory is absolutely essential and significantly increases the value of the sample. ## Popular Localities The only source of ilyukhinite specimens is the Lovozero Massif on the Kola Peninsula in Russia. This is the classic and only known locality for this mineral.

Care and storage

## Cleaning Specimens containing ilyukhinite, typically microscopic minerals on a rock matrix, should be cleaned with utmost care. It is recommended to use compressed air (from a safe distance) to remove dust. For more stubborn dirt, a soft brush and distilled water can be used, followed by thorough drying of the specimen. ## What to Avoid Avoid contact with acids and other aggressive chemicals, which can damage both ilyukhinite and its associated minerals. Ultrasonic cleaners should not be used, as they could cause small grains to detach from the matrix. The mineral is brittle, so it should be protected from impacts and scratching. ## Storage Micromount specimens are best stored in specialized "micromount" boxes, which protect them from dust and mechanical damage. Avoid exposure to extreme temperatures and humidity.

External references

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