Satimolite
Chemical formula: KNa<sub>2</sub>(Al<sub>5</sub>Mg<sub>2</sub>)[B<sub>12</sub>O<sub>18</sub>(OH)<sub>12</sub>](OH)<sub>6</sub>Cl<sub>4</sub>·4H<sub>2</sub>O
Satymolite is a rare, complex borate of potassium, sodium, aluminum, and magnesium, forming small, silky fibrous aggregates.
Properties
- Mohs hardness
- 1
- Luster
- Silky
- Streak
- White
- Density
- 2.16
- Cleavage
- None
- Fracture
- Fibrous
- Transparency
- Transparent to translucent
- Crystal system
- Hexagonal
Diagnostic features
## Identification The key diagnostic feature of satymolite is its mode of occurrence – white, silky aggregates composed of very fine, flexible fibers. Extremely low hardness (approximately 1 on the Mohs scale) and water solubility are also characteristic. However, identification requires confirmation by advanced analytical methods due to its similarity to other secondary salt minerals. ## Distinguishing from Similar Minerals Satymolite can be confused with other fibrous borates or sulfates found in salt domes, such as ginorite or ulexite. Ulexite also forms white, fibrous aggregates but is harder (2.5 on the Mohs scale). Final distinction from similar, rare minerals requires chemical analysis (EDS) or X-ray diffraction (XRD). ## Crystal Forms Satymolite forms clusters of thin, flexible fibers up to 1 cm long, which arrange into aggregates resembling cotton wool or felt. Well-formed, individual crystals are not observed.
Geological environment
## Genesis Satymolite is a secondary mineral, formed under specific conditions found within salt domes. It forms in the caprock clays covering rock salt deposits, in a boron-rich zone. Its formation is associated with the activity of groundwater reacting with salt minerals and surrounding rocks. ## Mineral Associations This mineral co-occurs with other minerals characteristic of an evaporitic environment. At the discovery locality, its association with halite, sylvite, ginorite, boracite, and anhydrite was noted. ## Localities The only known and confirmed occurrence of satymolite in the world is the Satymola salt dome in the Inder region, Atyrau Oblast, Kazakhstan. This is the type locality for this mineral.
Rarity
Very rare
For collectors
## Quality Criteria The quality of a satymolite specimen is primarily assessed based on the abundance and purity of the fibrous aggregates. The most desirable specimens are those with dense, white clusters of silky fibers, clearly visible on a piece of matrix rock. The size of the specimen and the absence of damage to the delicate fibers also significantly increase its collector's value. ## Popular Localities All collector specimens come from the only known locality – the Satymola salt dome in Kazakhstan. This mineral is not commercially extracted, and specimens available on the market originate from past scientific research or sporadic finds.
Care and storage
## Cleaning Due to its extreme softness and water solubility, satymolite should not be cleaned wet. Any contact with water, even distilled, can damage or destroy the specimen. Mechanical cleaning is also highly risky. The safest way to remove dust is by using a gentle stream of compressed air from a safe distance. ## What to Avoid Contact with water, acids, and any other chemicals must be strictly avoided. The mineral is hygroscopic and can absorb moisture from the air, leading to its degradation. It should be protected from high humidity, temperature changes, and direct sunlight. ## Storage Satymolite specimens must be stored in dry conditions, preferably in tightly sealed containers (e.g., "perky box" type) with a desiccant (e.g., silica gel). Due to its fragility and softness, it should be stored separately to avoid abrasions and mechanical damage.