Koryakite
Chemical formula: NaKMg₂Al₂(S⁶⁺O₄)₆
Koryakite is a rare sodium, potassium, magnesium, and aluminum sulfate, discovered in the fumaroles of Tolbachik volcano in Kamchatka.
Properties
- Mohs hardness
- 2-3
- Luster
- Vitreous
- Streak
- white
- Density
- 2.892
- Fracture
- Irregular/Uneven
- Transparency
- Transparent
- Crystal system
- Trigonal
Diagnostic features
## Identification Field identification of koryakite is practically impossible without advanced analysis. In a collection, it is identified based on its appearance (small, colorless, hexagonal tablets), very low hardness, and most importantly, its confirmed origin locality – the fumaroles of Tolbachik volcano. Final identification requires chemical (EDS) and X-ray (XRD) analysis. ## Distinguishing from Similar Minerals It can be confused with other colorless sulfates or halides found in the same environment, such as halite or sylvite. It is distinguished from them by its crystal habit (hexagonal tablets) and different chemical and physical properties, which, however, require specialized equipment for verification. ## Crystal Forms Koryakite forms small, tabular crystals with a hexagonal outline, often grouped into small aggregates.
Geological environment
## Genesis Koryakite is a volcanic mineral, formed by sublimation from volcanic gases in high-temperature fumaroles. It crystallizes directly from the gas phase on the walls of fumarole channels, at temperatures ranging from 360-450°C. ## Mineral Associations This mineral co-occurs with other sulfates and halides formed under similar conditions. At the type locality, it was found in association with minerals such as sanidine, hematite, tenorite, halite, sylvite, aphthitalite, langbeinite, arcanite, dravertite, and wulfenite. ## Localities The only confirmed occurrence of koryakite in the world is its type locality: Yadowitaya fumarole on the second cinder cone of the Great Fissure Eruption of Tolbachik volcano in Kamchatka, Russia.
Rarity
Extremely rare
For collectors
## Quality Criteria The quality of a koryakite specimen primarily depends on the size and development of its crystals. The most prized specimens are aggregates with clearly visible, sharp, tabular crystals, preferably set on a contrasting rock matrix. Due to the nature of the mineral, even the best specimens consist of crystals not exceeding fractions of a millimeter. ## Popular Localities The only source of koryakite specimens is its type locality on Tolbachik volcano in Kamchatka. Material from this locality is extremely difficult to obtain due to the inaccessibility of the terrain and the dangerous conditions in active fumarole fields.
Care and storage
## Cleaning Koryakite specimens are extremely delicate and potentially water-soluble. Cleaning should be limited to an absolute minimum. If necessary, a very soft brush can be used to dry-dust. All contact with water and other liquids should be avoided. ## What to Avoid Water, acids, detergents, and ultrasonics must be absolutely avoided. The mineral is very soft, susceptible to scratches and mechanical damage. It should be protected from moisture, high temperatures, and direct sunlight, which can lead to its degradation. ## Storage It is recommended to store koryakite specimens in sealed, airtight "micromount" boxes away from moisture and heat sources. Display should be in stable environmental conditions, preferably in a sealed display case with humidity control.