Yurgensonite
Chemical formula: K<sub>2</sub>Sn<sup>4+</sup>Ti<sup>4+</sup>O<sub>2</sub>(As<sup>5+</sup>O<sub>4</sub>)<sub>2</sub>
Yurgensonite is a rare tin and titanium arsenate, forming tiny, yellow crystals in volcanic fumaroles.
Properties
- Luster
- Vitreous
- Streak
- Light yellow
- Density
- 4.14
- Cleavage
- Perfect on {001}
- Transparency
- Transparent to translucent
- Crystal system
- Tetragonal
Diagnostic features
## Identification Identification of yurgensonite is possible almost exclusively using advanced laboratory methods, such as X-ray diffraction (XRD) and chemical analysis (EDS). In collector conditions, identification relies on a label from a trusted source and verification of the locality (Tolbachik volcano). Visual characteristics, such as light yellow color, tabular crystal habit, and occurrence in fumarolic paragenesis, are only indications. ## Distinguishing from similar minerals Yurgensonite can be confused with other rare, yellow secondary minerals from the same locality, such as arsenoflorencite-(Ce), shchurovskyite, or other arsenates. Certain distinction without specialized analysis is impossible. ## Crystal forms The mineral forms very small, thin, tabular crystals with a platy habit, often gathered in rosetted or radial aggregates. It also occurs as thin coatings and crusts.
Geological environment
## Genesis Yurgensonite is a volcanic mineral, crystallizing in the environment of high-temperature, oxidizing fumaroles. It forms through sublimation from volcanic gases rich in arsenic, tin, titanium, and potassium, at a temperature of approximately 450-500°C. It deposits on the surfaces of basaltic tuffs and lava crusts. ## Mineral associations It co-occurs with other fumarolic minerals such as hematite, tenorite, sanidine, arsenoflorencite-(Ce), baddeleyite, shchurovskyite, udinaite, johillerite, antofagastaite, and sylvite. ## Localities The only confirmed locality of yurgensonite in the world is its type locality - the Yadovitaya fumarole on the second cone of the northern breach of the Great Fissure Eruption of Tolbachik (1975-1976) on Tolbachik volcano, Kamchatka, Russia.
Rarity
Extremely rare
For collectors
## Quality criteria For such a rare mineral as yurgensonite, the most important criterion is its very presence and identifiability. Specimens with a larger surface area covered by the mineral, with more clearly formed, albeit still microscopic, crystals, are more valued. The aesthetics of the matrix rock and the richness of associated minerals are also important. ## Popular localities All known specimens come from a single location in the world - the fumarole of Tolbachik volcano in Kamchatka. Material from this locality is extremely difficult to obtain and is only available in specialized collections or from dealers specializing in rare minerals.
Care and storage
## Cleaning Yurgensonite specimens are extremely delicate and small, therefore mechanical or chemical cleaning is not recommended. Any attempts at cleaning risk irreversible damage or loss of material. They should be left in their untouched state. ## What to avoid Avoid contact with water, chemicals, ultrasound, and any vibrations or impacts. The mineral is sensitive to changes in temperature and humidity. Do not expose it to direct sunlight. ## Storage Storage requires specialized conditions. The safest way is to keep the specimen in its original, tightly sealed "micromount" container, away from dust, moisture, and temperature fluctuations. Display is only possible under a microscope.