Vladykinite

Chemical formula: Na₃Sr₄(Fe²⁺Fe³⁺)Si₈O₂₄

Vladykinite is a very rare sodium, strontium, and iron silicate, forming tiny, pinkish-brown grains in syenites.

## Characteristics Vladykinite is a complex silicate from the lamprophyllite group, occurring as very fine, anhedral (irregularly shaped) grains, usually not exceeding 0.5 mm in size. It is observed as a component of igneous rocks – syenites. Its grains are most often intergrown with other minerals, such as microcline or arfvedsonite. In thin sections under the microscope, it is colorless. ## Physical Properties This mineral is characterized by a hardness of 5 on the Mohs scale. Its density is approximately 3.51 g/cm³. It has a luster described as vitreous to greasy. It is a brittle mineral. ## Colors and Varieties The typical coloration of vladykinite is pinkish to grayish-brown. No varieties have been distinguished. ## History and Name The mineral is named in honor of Nikolay Vasilievich Vladykin (born 1940), a Russian geologist and mineralogist from the Institute of Geochemistry in Irkutsk, for his contributions to the study of alkaline massifs, including the Murun Massif, where this mineral was discovered. It was approved as a new mineral species by the IMA in 2011 (IMA2011-065). ## Uses Vladykinite has no industrial application. Due to its extreme rarity and inconspicuous appearance, it is of interest only to specialized collectors and scientific institutions.

Properties

Mohs hardness
5
Luster
Vitreous to greasy
Streak
White
Density
3.51
Cleavage
On {100}
Transparency
Transparent to translucent
Crystal system
Monoclinic

Diagnostic features

## Identification Identification of vladykinite is impossible without advanced analytical methods, such as X-ray microanalysis (EDS/WDS) or X-ray diffraction (XRD). Under collecting conditions, identification relies solely on trust in a label from a reliable source confirming scientific analysis. Visually, they are only very fine, pinkish-brown grains in the rock. ## Distinguishing from Similar Minerals Visually, it is indistinguishable from many other rare minerals with similar habit and color, found in alkaline massifs, such as tinaksite, charoite, or some members of the eudialyte group. Definitive differentiation requires specialized laboratory equipment. ## Crystal Forms Vladykinite forms exclusively anhedral, irregular grains and granular aggregates. No well-formed crystals have been observed.

Geological environment

## Genesis Vladykinite is a mineral of magmatic origin. It forms in the late stages of crystallization in a specific type of alkaline rock – aegirine-kalsilite syenites, rich in potassium and sodium. ## Mineral Associations This mineral coexists with other minerals typical of the Murun Massif, such as microcline, aegirine, arfvedsonite, nepheline, kalsilite, lamprophyllite, tinaksite, as well as rarer minerals like tausonite (strontium titanate). ## Localities The only confirmed occurrence of vladykinite in the world is its type locality – the Murun Massif (Tausonitovaya Gorka hill) on the Aldan Shield, at the border of the Irkutsk Oblast and Yakutia in Russia.

Rarity

Extremely rare

For collectors

## Quality Criteria The quality of a vladykinite specimen depends solely on the abundance and size of its grains within the host rock (matrix). Since the mineral is microscopic, fragments of rock where its aggregates are visible to the naked eye as distinct, pinkish-brown spots are most valued. Co-occurrence with other rare minerals from this locality enhances its attractiveness. ## Popular Localities All material available on the collector's market comes from a single location in the world – the Murun Massif in Russia. These specimens are extremely difficult to acquire.

Care and storage

## Cleaning Specimens containing vladykinite should generally not be cleaned, as its fine grains are intergrown with the host rock. Any mechanical or chemical intervention risks damaging or completely removing them. If necessary, dust can be removed with a gentle stream of compressed air. ## What to Avoid Avoid contact with all chemicals, acids, and detergents. Do not subject the specimen to ultrasonic cleaning or steam cleaning. The mineral is brittle, so protect it from impacts and scratches. ## Storage Specimens with vladykinite are best stored in stable conditions, in a closed display box, to protect them from dust and mechanical damage. An accurate label with the location should be included, as visual identification is impossible.

External references

Sources

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