Bellingerite

Chemical formula: Cu²⁺₃(I⁵⁺O₃)₆·2H₂O

Bellingerite is a very rare, bright green copper iodate, forming small, prismatic crystals with a vitreous luster.

## Characteristics Bellingerite is a hydrated copper iodate that visually stands out with its intense, bright green or emerald green color. It occurs as small, prismatic or tabular crystals, rarely exceeding 1 mm in length. These crystals often form radial aggregates, rosettes, or crusts on the surface of host rocks. Due to its size, magnification is usually necessary for observation. ## Physical Properties This mineral is characterized by a hardness of approximately 4 on the Mohs scale. Its crystals have a vitreous luster and are transparent to translucent. The density of bellingerite is about 4.79 g/cm³. It is a brittle mineral with an uneven fracture. ## Colors and Varieties Bellingerite occurs in a characteristic, uniform color ranging from bright green to emerald green. No color or commercial varieties are known. ## History and Name The mineral was first described in 1940 by Harry Berman and C. W. Wolfe. Its name honors Herman Carl Bellinger (1867-1941), vice president of the Chile Exploration Company, which managed the Chuquicamata mine in Chile, where the discovery was made. ## Uses Bellingerite has no industrial application. Its significance is purely scientific and collectible; it is valued by collectors specializing in rare minerals or minerals from specific localities.

Properties

Mohs hardness
4
Color
Green, light green; light bluish green in transmitted light
Luster
Vitreous
Streak
Very light green
Density
4.88
Cleavage
Perfect on {100}
Fracture
Sub-Conchoidal
Transparency
Transparent to translucent
Crystal system
Triclinic

Diagnostic features

## Identification Bellingerite can be identified by its intense green color, small, prismatic crystals often forming radial aggregates, and vitreous luster. The locality is key – it is a secondary mineral found in the oxidation zones of copper deposits in arid, dry desert areas. ## Distinguishing from Similar Minerals It can be confused with other green secondary copper minerals, such as brochantite, atacamite, or antlerite. Differentiation often requires chemical analysis (test for the presence of iodine) or crystallographic analysis. Bellingerite is distinguished by its triclinic crystal system and specific crystal habit. Unlike copper carbonates (malachite), it does not react with hydrochloric acid. ## Crystal Forms Bellingerite crystals are prismatic, often flattened and elongated. They typically occur as radial or stellate aggregates, as well as fine crusts and veinlets.

Geological environment

## Genesis Bellingerite is a secondary mineral, formed in extremely dry, desert climatic conditions. It forms in the oxidation zones of copper sulfide deposits, where iodate-rich waters (likely originating from the decomposition of organic matter or atmospheric dust) react with copper minerals. ## Mineral Associations It most commonly co-occurs with other iodates, such as salesite, as well as with sulfates (brochantite, antlerite, chalcanthite), chlorides (atacamite), and gypsum and quartz. ## Localities The most important and classic locality for bellingerite is the Chuquicamata mine in the Antofagasta region of Chile. This is its type locality, from which the best-known specimens originate. It has also been identified in several other locations in the Atacama Desert.

Rarity

Very rare

For collectors

## Quality Criteria The most prized bellingerite specimens are those with well-formed, sharp crystals forming aesthetic, radial aggregates. The intensity and purity of the green color also increase its value. Contrast with the rock matrix and lack of damage to the delicate crystals are important. Due to the small size of the crystals, specimens are usually evaluated as "micromounts." ## Popular Localities The only source of specimens of collector significance is the Chuquicamata mine in Chile. Specimens from this locality are considered classic and most desirable.

Care and storage

## Cleaning Bellingerite specimens should be cleaned with utmost care, using only compressed air to remove dust. Due to its water solubility, contact with water and other liquids must be strictly avoided. ## What to Avoid Avoid contact with water, acids, and any chemical agents that could damage or dissolve it. The mineral is brittle, so it should be protected from impacts, vibrations, and abrasion. It should not be heated or exposed to ultrasound. ## Storage Bellingerite specimens are best stored in enclosed, stable "micromount" containers that protect them from dust, humidity, and mechanical damage. Avoid storage in areas with high air humidity.

External references

Sources

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