Chesnokovite

Chemical formula: Na₂SiO₂(OH)₂·8H₂O

Chesnokovite is a rare, hydrated sodium silicate, forming colorless, tabular crystals with perfect cleavage, found in alkaline pegmatites.

## Characteristics Chesnokovite is a hydrated sodium silicate that crystallizes as colorless, transparent to translucent crystals. It typically forms thin, tabular crystals with a rectangular or lath-like outline, often aggregated into radial or chaotic clusters. Due to its delicate nature and high water content, it is an unstable mineral under ambient conditions, making it difficult to preserve and rare in collections. ## Physical Properties This mineral is characterized by a low hardness of 2.5 on the Mohs scale, meaning it is very soft and easily scratched. Its density is also very low, at 1.68 g/cm³, which is comparable to the density of ice. The luster on crystal surfaces is vitreous, and on cleavage planes, it can be pearly. ## Colors and Varieties Chesnokovite is usually colorless. No colored varieties or trade names are distinguished. ## History and Name The mineral was named after Boris Valentinovich Chesnokov (1928-2005), a Russian mineralogist and professor at the State Mining Institute in St. Petersburg. It was approved as a new mineral species by the International Mineralogical Association (IMA) in 2006. The type locality where it was first identified is Mount Kedykverpakhk in the Lovozero Massif, Russia. ## Applications Chesnokovite has no industrial applications. Its significance is purely scientific and as a collector's item, although due to its instability, it is very rarely found in collections.

Properties

Mohs hardness
2.5
Luster
Vitreous, Pearly
Streak
White
Density
1.68
Cleavage
Perfect on {010}, good on {100} and {001}.
Fracture
Conchoidal,Step-Like
Transparency
Transparent,Translucent
Crystal system
Orthorhombic

Diagnostic features

## Identification Chesnokovite can be identified by its characteristic thin, tabular crystals, often forming radial aggregates. Key features include very low hardness (2.5), perfect cleavage in one direction, low density, and instability in dry air, leading to disintegration. It reacts with water. ## Distinguishing from Similar Minerals Minerals such as gypsum or muscovite can form similar colorless, tabular crystals with perfect cleavage. Chesnokovite differs from them by its significantly lower hardness and extreme instability under atmospheric conditions – a characteristic not exhibited by other similar minerals. ## Crystal Forms Crystals are tabular, flattened parallel to {010}, with a rectangular or lath-like outline. They form fan-shaped, radial, or chaotically arranged aggregates, as well as thin veins.

Geological environment

## Genesis Chesnokovite is a hydrothermal mineral. It forms in the late stages of crystallization in agpaitic pegmatites (highly alkaline, rich in sodium, and poor in silica). It forms in cavities and fissures within these rocks. ## Mineral Associations This mineral co-occurs with other rare alkaline minerals. At the type locality, it was found in association with natrosilite, villiaumite, rasvumite, lomonosovite, vuonnemite, zorite, and revdite. ## Localities The only confirmed and described occurrence of chesnokovite in the world is its type locality – Mount Kedykverpakhk in the Lovozero Massif, on the Kola Peninsula in the Murmansk Oblast, Russia.

Rarity

Extremely rare

For collectors

## Quality Criteria Due to its extreme rarity and instability, any well-preserved chesnokovite specimen is valuable. The most desirable specimens are those with distinct, transparent crystals forming aesthetic, radial aggregates. It is important that the specimen shows no signs of dehydration (clouding, disintegration). The presence of associated minerals, especially rare ones, also increases its scientific and collector's value. ## Popular Localities The only source of chesnokovite specimens is the Lovozero Massif on the Kola Peninsula in Russia. This is the classic and sole locality for this mineral.

Care and storage

## Cleaning Chesnokovite specimens are extremely sensitive to changes in humidity and temperature. They should not be cleaned with water or any other liquids, as the mineral is soluble and easily dehydrates. Dust can only be removed very carefully using a soft brush or a stream of compressed air from a distance. ## What to Avoid Contact with water and chemicals must be strictly avoided. The mineral is unstable in dry air and at room temperature – it loses its water of crystallization, disintegrating and turning white. It must not be heated or exposed to direct sunlight. ## Storage Chesnokovite requires storage under special conditions. It is best kept in a tightly sealed container to maintain high relative humidity and prevent dehydration. Some specimens are stored in inert liquids (e.g., paraffin oil) to isolate them from the air. Display is very difficult and not recommended.

External references

Sources

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