Javorieite

Chemical formula: KFe<sup>2+</sup>Cl<sub>3</sub>

Javoryite is an extremely rare potassium iron chloride, forming microscopic, brown crystals in volcanic exhalations.

## Characteristics Javoryite is a halide mineral, chemically an anhydrous potassium iron chloride. It occurs as very small, bladed or acicular crystals, rarely exceeding fractions of a millimeter in length. It typically forms small, radial aggregates, crusts, or appears as single, scattered crystals on the rock surface. Its brown to reddish-brown color is characteristic, although due to the size of the crystals, magnification is necessary for observation. ## Physical Properties Javoryite crystals exhibit a vitreous luster, sometimes described as slightly resinous. They are translucent, becoming opaque in thicker aggregates. The mineral's density, calculated based on its composition and crystal structure, is approximately 2.7 g/cm³. Hardness has not been precisely determined due to the small size and fragility of the crystals. ## Colors and Varieties This mineral is monochromatic – it occurs in shades from brown to reddish-brown. No color varieties or commercial varieties have been distinguished. ## History and Name Javoryite was officially recognized as a new mineral species by the International Mineralogical Association (IMA) in 2016. Its name comes from the discovery locality – the Javorie stratovolcano in Slovakia. It was described by a team of mineralogists led by Pavel Bačík. ## Applications Javoryite has no industrial application. Its significance is purely scientific and collectible, being an object of interest for specialists in fumarolic minerals and micromineral collectors.

Properties

Luster
Vitreous
Streak
Light brown
Density
2.70
Cleavage
Perfect on {010}
Transparency
Translucent to Opaque
Crystal system
Orthorhombic

Diagnostic features

## Identification Amateur identification of javoryite is practically impossible. Key features include its specific occurrence environment (volcanic fumaroles), brown color, and small, bladed crystals. Definitive identification requires advanced analytical methods such as X-ray diffraction (XRD) or chemical microanalysis (EDS). ## Differentiation from Similar Minerals Javoryite can be confused with other rare iron chlorides and oxides found in fumaroles. Differentiation from minerals such as kremersite or eryosfalite requires specialized laboratory equipment. Analysis of associated minerals can be helpful. ## Crystal Forms It forms elongated, bladed or acicular crystals with a rectangular cross-section. These crystals often arrange into small, radial or chaotic aggregates and crusts.

Geological environment

## Genesis Javoryite is a fumarolic mineral. It forms by sublimation from hot volcanic gases (exhalations) at temperatures ranging from 200 to 400°C. It crystallizes directly on the surfaces of volcanic rocks near fumarole vents. ## Mineral Associations This mineral co-occurs with other halides and sulfates formed under similar conditions. It is most commonly associated with sylvite, halite, kremersite, rinneite, and hematite. ## Localities As an extremely rare mineral, javoryite has been confirmed in only a few locations worldwide. The main localities are: - Javorie stratovolcano in central Slovakia (type locality). - Fumaroles of Tolbachik volcano on the Kamchatka Peninsula, Russia.

Rarity

Extremely rare

For collectors

## Quality Criteria Javoryite is a mineral exclusively for micromineral collectors (so-called "micromounts"). The value of a specimen is determined by the richness and abundance of crystals on the rock matrix, their size (although always sub-millimeter dimensions), sharpness of form, and lack of damage. Specimens with well-formed, single crystals or aesthetic aggregates are highly prized. ## Popular Localities The most known and valued specimens come from two main localities: Tolbachik volcano in Kamchatka, which provided rich micromineralogical specimens, and the type locality in Slovakia.

Care and storage

## Cleaning This mineral is hygroscopic and likely water-soluble. **Absolutely avoid contact with water and other liquids.** Cleaning is highly inadvisable. If dust removal is necessary, a soft, dry brush or careful blowing with a photographic air blower can be used. ## What to Avoid Above all, avoid moisture, water vapor, and direct contact with water, which can permanently damage or destroy the specimen. Ultrasonic cleaning and exposure to any chemicals are also not recommended. Store away from heat sources. ## Storage Javoryite specimens must be stored in dry conditions. It is recommended to keep them in tightly sealed containers, such as "perky boxes," preferably with a desiccant (silica gel). Protect from dust and sudden temperature changes.

Sources

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