Chlorbartonite

Chemical formula: K₆Fe₂₄S₂₆Cl

Chlormanganokalite is a rare potassium, manganese, and iron chloride, forming small, hexagonal crystals in volcanic environments.

## Characteristics Chlormanganokalite is a halide group mineral characterized by a complex chemical composition containing potassium, manganese, and iron. It occurs as very small, hexagonal, tabular crystals that rarely exceed 0.2 mm. These crystals often form aggregates or thin coatings on the surface of other minerals. Due to their size, visual features are difficult to observe without a microscope. ## Physical Properties This mineral is very soft, with a Mohs hardness of 2. It has a vitreous luster and is transparent. The density calculated based on the chemical formula and unit cell parameters is approximately 3.33 g/cm³. It is fusible and readily dissolves in water. ## Colors and Varieties Chlormanganokalite typically ranges in color from orange-brown to reddish-brown. No varieties have been distinguished. ## History and Name The mineral was discovered in volcanic exhalations at Tolbachik volcano in Kamchatka, Russia. It was approved by the International Mineralogical Association (IMA) in 1981. Its name refers to its chemical composition – the presence of chlorine (chloro) and manganese (mangano) – and its structural relationship to potassium chloride, known as sylvite (kalite).

Properties

Mohs hardness: 2
Luster: Vitreous
Streak: Light brown
Density: 3.33
Cleavage: Perfect on {0001}
Fracture: Uneven
Transparency: Transparent
Crystal system: Trigonal

Diagnostic features

## Identification Amateur identification of chlormanganokalite is practically impossible due to the microscopic size of its crystals and its occurrence in complex parageneses. Key features include its orange-brown color, hexagonal crystal shape (visible under a microscope), low hardness, and occurrence in volcanic fumarole environments. The mineral is highly hygroscopic. Definitive confirmation requires advanced analytical methods, such as X-ray diffraction (XRD) and chemical analysis (EDS). ## Distinguishing from Similar Minerals It can be confused with other rare halides found in similar environments, such as erychrosiderite, mitscherlichite, or kremersite. Differentiation relies on precise chemical composition analysis and crystallographic data. ## Crystal Forms It forms very small, tabular crystals with a hexagonal outline. They occur as single, dispersed crystals or form thin coatings and crusts.

Geological environment

## Genesis Chlormanganokalite is a mineral of volcanic origin. It forms through sublimation from volcanic gases (exhalations) in active fumarole zones, at temperatures ranging from 150 to 450°C. It crystallizes directly from the gas phase on the surface of volcanic rocks. ## Mineral Associations This mineral co-occurs with other volcanic exhalation products, such as halite, sylvite, carnallite, hematite, tenorite, erychrosiderite, mitscherlichite, and kremersite. ## Localities The only confirmed locality for chlormanganokalite worldwide is its type locality – the fumarole field of the second cinder cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption on Tolbachik volcano, Kamchatka, Russia.

Rarity

Extremely rare

For collectors

## Quality Criteria The quality of a chlormanganokalite specimen is determined by the abundance and visibility of crystals on the rock matrix. The most desirable specimens are those with clearly formed, though still microscopic, crystals of an intense, orange-brown color. Due to its extreme rarity, any authentic specimen, even in the form of a small coating, holds significant scientific and collector value. ## Popular Localities The only known source of specimens is Tolbachik volcano in Kamchatka, Russia. Material from this locality is extremely difficult to acquire and is a prized possession in specialized systematic collections and those dedicated to volcanic minerals.

Care and storage

## Cleaning Due to its extreme sensitivity to water, this mineral must not be cleaned wet. Any contaminants should be removed only mechanically, dry, using a very soft brush or compressed air from a safe distance. ## What to Avoid Contact with water, water vapor, and high air humidity must be strictly avoided, as the mineral is hygroscopic and easily dissolves. It should be protected from all chemicals, acids, and cleaning agents. It is sensitive to heat. ## Storage Chlormanganokalite specimens must be stored in hermetically sealed containers, preferably with a desiccant (e.g., silica gel). They should be kept at a stable room temperature, away from sources of light and heat.

Sources

IMA Mineral List (CNMNC)