Flinteite

Chemical formula: K₂Zn²⁺Cl₄

Flinkite is a rare, water-soluble potassium and zinc halide, forming colorless crystals in volcanic fumarole environments.

## Characteristics Flinkite is a very rare mineral from the halide group. It forms small, colorless, tabular or prismatic crystals, often aggregated into crusts or granular masses. Due to its water solubility, it is an unstable mineral in humid environments and occurs exclusively in active, high-temperature volcanic fumaroles, where it crystallizes directly from gases. ## Physical Properties Flinkite crystals exhibit a vitreous luster. The mineral is relatively soft and light. Its most characteristic physical feature is its complete solubility in water, which prevents its preservation under conditions other than the dry environment of its formation. ## Colors and Varieties Flinkite is colorless. No colored varieties are known. ## History and Name The mineral was approved by the IMA in 2016. Its name honors Evgeny Evgenievich Flink (1845–1931), a Russian mineralogist and curator of the mineralogical collections of the Russian Academy of Sciences, in recognition of his contribution to the study of minerals from the Khibiny complex on the Kola Peninsula. ## Applications Flinkite has no industrial applications. Its significance is purely scientific and as a collector's item, as an example of a rare and unstable mineral forming under specific volcanic conditions.

Properties

Mohs hardness
2
Color
Light green, light yellow to bright greenish-yellow , colourless
Luster
Vitreous
Streak
White
Density
2.49
Cleavage
One direction of distinct cleavage was observed
Fracture
Uneven
Transparency
Transparent
Crystal system
Orthorhombic

Diagnostic features

## Identification The key diagnostic feature of flinkite is its complete and rapid solubility in water. In field conditions, identification is aided by its occurrence as colorless, vitreous coatings and crystals in active, hot volcanic fumaroles. However, confirmation requires advanced analytical methods, such as X-ray diffraction (XRD). ## Differentiation from Similar Minerals Flinkite can be confused with other soluble halides found in fumaroles, such as Sylvite (KCl) or Halite (NaCl). Distinguishing them "by eye" is practically impossible without a chemical test for the presence of zinc or crystallographic analysis. Unlike the isometric crystals of Halite and Sylvite, flinkite crystallizes in the orthorhombic system. ## Crystal Forms The mineral forms tabular or short prismatic crystals, reaching up to 0.3 mm. It most often occurs as fine-grained or powdery aggregates and crusts on lava surfaces.

Geological environment

## Genesis Flinkite is a volcanic mineral, formed by sublimation. It crystallizes directly from hot gases (at temperatures of 450-600°C) in volcanic fumarole exhalations. It is a product of the reaction of volatile alkali metal and zinc chlorides. ## Mineral Associations This mineral co-occurs with other sublimation halides, such as Halite (NaCl), Sylvite (KCl), Carnallite (KMgCl₃·6H₂O), Sangarite, Eriochalcite (CuCl₂), and Mitscherlichite (K₂CuCl₄·2H₂O). ## Localities The only confirmed occurrences of flinkite in the world are the active fumaroles of Tolbachik volcano on the Kamchatka Peninsula in Russia. It was identified in the "Arsenatnaya" and "Yadovitaya" fumaroles on the second cone of the northern breach of the Great Tolbachik Fissure Eruption of 2012-2013.

Rarity

Very rare

For collectors

## Quality Criteria The collector's appeal of flinkite specimens primarily depends on the richness and visibility of crystals on the rock matrix. Most valued are samples with well-formed, though microscopic, colorless crystals forming druses or dense coatings. Due to the rarity of the mineral, every authentic and well-documented specimen has high value for specialized collectors. ## Popular Localities The only source of flinkite specimens is the Tolbachik volcanic complex in Kamchatka. All samples available on the collector's market originate from this single location in the world.

Care and storage

## Cleaning This mineral must absolutely not be cleaned wet. Any contact with water, even a damp cloth, will cause it to immediately dissolve and be destroyed. Only very careful removal of dust with a soft, completely dry brush or a stream of dry air is permissible. ## What to Avoid Avoid water, moisture, water vapor, and all chemical solutions. The mineral is hygroscopic, meaning it absorbs moisture from the air, so it must be protected from humid environments. It should also be protected from mechanical damage due to its softness. ## Storage Flinkite specimens must be stored in hermetically sealed containers (e.g., "perky box" type) or in specialized display cases with controlled, low humidity. It is recommended to place a desiccant, such as silica gel, in the container.

External references

Sources

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