Shakhovite

Chemical formula: Hg<sup>1+</sup><sub>4</sub>Sb<sup>5+</sup>O<sub>3</sub>(OH)<sub>3</sub>

Shakhovite is a very rare, secondary mercury and antimony mineral, forming tiny, yellow crystals in the oxidation zones of mercury deposits.

## Characteristics Shakhovite is an oxide mineral that typically occurs as very small, tabular or prismatic crystals, rarely exceeding 1 mm. It forms aggregates in the form of coatings, crusts, or small druses in rock cavities. Its crystals are transparent to translucent and are characterized by an intense, lemon-yellow to canary-yellow color. ## Physical Properties This mineral is relatively soft, with a Mohs hardness of approximately 2. It has an adamantine luster, which gives it high brilliance despite the small size of its crystals. It is a heavy mineral due to its high mercury content, and its density is approximately 8.38 g/cm³. ## Colors and Varieties Shakhovite occurs in various shades of yellow, from lemon to canary. No color or commercial varieties are distinguished. ## History and Name The mineral was discovered in the Khaidarkan mercury deposit in Kyrgyzstan and first described in 1980. Its name honors Felix Nikolaevich Shakhov (1894–1971), a Russian geologist and specialist in ore deposit geology, a member of the USSR Academy of Sciences. ## Uses Shakhovite has no industrial application due to its extreme rarity and small size. It is of purely scientific importance and is a prized collector's mineral.

Properties

Mohs hardness
2
Luster
Adamantine
Streak
Pale yellow
Density
8.38
Cleavage
Perfect on {100}
Fracture
Uneven
Transparency
Transparent to translucent
Crystal system
Orthorhombic

Diagnostic features

## Identification Key diagnostic features of shakhovite include its intense, lemon-yellow color, adamantine luster, high density, and occurrence as tiny, tabular crystals in association with other mercury minerals. ## Distinguishing from Similar Minerals Shakhovite can be confused with other yellow secondary mercury minerals, such as terlinguaite or eglestonite. Differentiation requires advanced analytical methods, such as X-ray diffraction (XRD). For collectors, proper identification from the locality of origin is fundamental. ## Crystal Forms Shakhovite crystals are usually very small, with a tabular or short-prismatic habit. They often form radial aggregates, rosettes, or druses lining small fissures and cavities in the host rock.

Geological environment

## Genesis Shakhovite is a secondary mineral, forming in the oxidation zones of hydrothermal mercury-antimony deposits. It forms as a result of the weathering of primary ores containing mercury and antimony under low temperature and pressure conditions. ## Mineral Associations This mineral co-occurs with other secondary mercury and antimony minerals. Its most common associates include calomel (Hg₂Cl₂), native mercury (Hg), kuznetsovite (Hg₆As₂Cl₂O₉), cordierite, as well as cinnabar (HgS) and stibnite (Sb₂S₃) as primary minerals. ## Localities The most important and typical occurrence of shakhovite is the Khaidarkan mercury deposit in the Alai Valley in Kyrgyzstan. This is the only confirmed and well-documented locality for this mineral in the world.

Rarity

Very rare

For collectors

## Quality Criteria The most valuable shakhovite specimens are those with well-formed, sharp crystals of intense, lemon-yellow color and strong luster. Rich crystalline aggregates and druses covering a larger surface of the rock matrix are highly prized. Contrast with dark host rock also enhances the specimen's attractiveness. ## Popular Localities The only source of collector specimens is the historical Khaidarkan deposit in Kyrgyzstan. All valuable specimens on the market originate from this single locality.

Care and storage

## Cleaning Due to its toxicity and reactivity, cleaning shakhovite is not recommended. If absolutely necessary, compressed air can be used to remove loose dust. Contact with water and any chemicals should be avoided. ## What to Avoid Contact with water, acids, and other chemicals must be strictly avoided. The mineral is sensitive to light, which can cause it to darken and decompose. It should be protected from high temperatures and humidity changes. Due to its mercury content, it is toxic – inhalation of dust and direct skin contact should be avoided. ## Storage Shakhovite specimens must be stored in airtight, dark containers to prevent exposure to light and moisture. It is best to keep them in stable conditions, away from heat sources. Storage in separate, labeled boxes is recommended due to its toxicity.

Sources

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