Kasatkinite
Chemical formula: Ba₂Ca₈B₅Si₈O₃₂(OH)₃·6H₂O
A rare barium and calcium borosilicate, forming colorless or white, platy crystals aggregated into radial clusters.
Properties
- Mohs hardness
- 3
- Luster
- Vitreous, Silky
- Streak
- White
- Density
- 3.11
- Cleavage
- Perfect on {010}
- Fracture
- Splintery
- Transparency
- Transparent to translucent
- Crystal system
- Monoclinic
Diagnostic features
## Identification A characteristic feature of kasatkinite is its white, radial aggregates of small, platy crystals with a silky luster. Key for identification is the strong, blue-white fluorescence under shortwave UV light. The mineral is also flexible and dissolves in acids. ## Distinguishing from Similar Minerals Kasatkinite can be confused with other white, fibrous or radial minerals from hydrothermal zones, such as pectolite, wollastonite, or zeolites (e.g., natrolite). It is distinguished from them by a combination of the following features: strong fluorescence in UV-SW, flexibility of crystals, and co-occurrence with other boron minerals in a specific calc-silicate rock environment. ## Crystal Forms Crystals are elongated, platy or acicular, up to 1 mm long. They typically form radial, stellate, or spherulitic (spherical) aggregates.
Geological environment
## Genesis Kasatkinite forms under hydrothermal conditions within calc-silicate rocks (magnesian skarns) that have undergone boron metasomatism. It forms in cavities and fissures within these rocks. ## Mineral Associations This mineral co-occurs with calcite, dolomite, magnetite, diopside, phlogopite, as well as other rare boron minerals such as harkerite, kurchatovite, sakhaite, and szaibelyite. ## Localities The only confirmed locality of kasatkinite in the world is its type locality – the Korshunovskoye iron ore deposit, located near the city of Zheleznogorsk-Ilimsky in Irkutsk Oblast, Siberia, Russia.
Rarity
Very rare
For collectors
## Quality Criteria The quality of kasatkinite specimens is assessed based on the size and development of the radial aggregates. The most desirable specimens are those with distinct, spherical or stellate clusters on a contrasting matrix. Due to the microscopic nature of the mineral, the aesthetics of the entire mineral assemblage, rather than individual crystals, are crucial. ## Popular Localities The only source of specimens of this mineral is the Korshunovskoye deposit in Russia. All kasatkinite available on the collector's market originates from this single locality.
Care and storage
## Cleaning Specimens should be cleaned very carefully, using compressed air to remove dust. Due to the delicate nature of the aggregates and solubility in acids, any contact with water and chemical agents is discouraged. ## What to Avoid Contact with acids, in which the mineral rapidly dissolves, must be strictly avoided. The crystals are brittle and susceptible to mechanical damage. Specimens should be protected from vibrations and impacts. ## Storage It is recommended to store specimens in stable, sealed "micromount" containers, which protect them from dust, moisture, and physical damage. Exposure to humid air should be avoided.