Vitimite

Chemical formula: Ca₆B₁₄O₁₉(S₆+O₄)(OH)₁₄·₅H₂O

Vitimite is an extremely rare, hydrated calcium borate, forming colorless, acicular crystals aggregated into radial clusters.

## Characteristics Vitimite is a complex, hydrated calcium borate from the sulfatoborate group. It forms characteristic, radial or fibrous aggregates that can reach up to 2-3 cm in diameter. These are composed of very fine, acicular and elongated crystals. Specimens are usually colorless and transparent, with a vitreous luster, which gives the aggregates a delicate, almost silky appearance. ## Physical Properties This mineral is transparent and characterized by a vitreous luster. Its calculated density is approximately 2.25 g/cm³. Hardness has not been precisely determined, but due to its acicular structure and chemical composition, it can be assumed to be a relatively soft and brittle mineral. ## Colors and Varieties Vitimite is a colorless mineral. No colored varieties or trade names are known. ## History and Name The mineral's name comes from its discovery locality - the Vitim Plateau in Buryatia, Russia. It was first described in 1996 by a team of mineralogists led by S.V. Malinko. ## Applications Due to its extreme rarity, vitimite has no industrial applications. It is solely an object of scientific interest and a prized acquisition for advanced systematic and regional mineral collections.

Properties

Luster: Vitreous
Streak: White
Density: 2.25
Transparency: Transparent
Crystal system: Monoclinic

Diagnostic features

## Identification The characteristic features of vitimite are radial aggregates composed of colorless, transparent, acicular crystals with a vitreous luster. Its specific occurrence environment – borate skarns – is also crucial for identification. ## Distinguishing from Similar Minerals Vitimite can be confused with other acicular borates, such as ulexite. However, ulexite often forms larger, fibrous aggregates with a silky luster and exhibits the characteristic "television stone" optical effect, which vitimite does not possess. Definitive differentiation from similar rare borates requires advanced analyses, e.g., X-ray diffraction (XRD). ## Crystal Forms Vitimite crystals are strongly elongated and acicular. They occur almost exclusively in the form of radial, fibrous, or spherulitic aggregates.

Geological environment

## Genesis Vitimite is a metasomatic mineral. It forms in contact zones between granitoid intrusions and carbonate rocks (dolomitic marbles), within a skarn-type boron deposit. ## Mineral Associations This mineral coexists with other borates, such as szaibelyite, sibirskite, hydroboracite, and ulexite. It is also accompanied by calcite, fluorite, and sulfide minerals. ## Localities The only confirmed locality of vitimite in the world is its type locality – the Solongo boron deposit on the Vitim Plateau in Buryatia, Russia.

Rarity

Extremely rare

For collectors

## Quality Criteria The most highly valued vitimite specimens are those that display well-formed, dense, radial aggregates with a distinct luster. The size of the aggregate and its placement on a contrasting rock matrix are important. Co-occurrence with other rare borate minerals from the same locality adds additional value. ## Popular Localities As this mineral comes from only one place in the world, all collector specimens originate from the Solongo deposit in Russia.

Care and storage

## Cleaning Vitimite specimens are very delicate and sensitive. For dust removal, use only a soft brush or compressed air from a safe distance. Avoid contact with water, as being a hydrated borate, it may partially dissolve or change its structure. ## What to Avoid This mineral is sensitive to high temperatures, which can cause dehydration and destruction. It should be protected from all acids and chemicals, which can easily damage it. Due to its acicular form and brittleness, it is very susceptible to mechanical damage. ## Storage It is recommended to store specimens in closed, stable containers or display cases to protect them from dust, moisture, and physical damage. Avoid exposure to direct sunlight or sudden temperature changes.

Sources

IMA Mineral List (CNMNC)