Iranite

Chemical formula: Pb²⁺₁₀Cu²⁺(Cr⁶⁺O₄)₆(SiO₄)₂(OH)₂

Iranite is a very rare, saffron-yellow lead, copper, and chromium mineral, discovered in Iran, from which it derives its name.

## Characteristics Iranite is a hydrated lead-copper chromate-silicate. It forms very small, tabular or bladed crystals, rarely exceeding 1 mm in length. It typically occurs as radial aggregates, rosettes, or thin crusts on the host rock. Its most distinctive feature is its intense, saffron-yellow color. ## Physical Properties This mineral is relatively soft, with a Mohs hardness of 3. It has a resinous to adamantine luster and is transparent to translucent. Due to the small size of its crystals, precisely determining many physical properties is difficult. ## Colors and Varieties Iranite occurs in a characteristic saffron-yellow color. No color varieties or commercial varieties are known. ## History and Name The mineral's name comes from Iran, where it was first discovered. It was described by P. Bariand and P. Herpin in 1963 based on specimens found in the Sebarz mine in the Anarak district. ## Uses Iranite has no industrial application. Due to its rarity, attractive color, and mode of occurrence, it is a mineral valued exclusively by collectors specializing in rare species (so-called "systematists") and microminerals.

Properties

Mohs hardness
3
Color
Saffron-yellow
Density
0
Crystal system
Triclinic

Diagnostic features

## Identification Iranite can be identified by its characteristic saffron-yellow color, resinous luster, and typical forms of occurrence – radial aggregates of small, tabular crystals. It is a secondary mineral found in the oxidation zones of lead deposits. ## Distinguishing from Similar Minerals Iranite can be confused with other secondary lead minerals of yellow color, such as wulfenite or mimetite. It differs from them in crystal habit (small, tabular in radial aggregates) and its specific saffron hue. However, definitive identification requires advanced analytical methods, such as Raman spectroscopy or EDS analysis. ## Crystal Habits Crystals are very small, tabular or bladed, often flattened. They usually form radial or stellate aggregates and rosettes, as well as thin coatings on rock surfaces.

Geological environment

## Genesis Iranite is a secondary mineral, forming in the oxidation zones (gossans) of hydrothermal lead and copper ore deposits, in the presence of chromium minerals. It forms under arid and desert conditions. ## Mineral Associations It most often co-occurs with other secondary lead and chromium minerals. At its type locality (Sebarz, Iran), it was found in association with diaboleite, fornacite, wulfenite, mimetite, and cerussite. ## Localities The most important and type locality is the Sebarz mine in Isfahan Province, Iran. Its presence has also been confirmed in several other locations worldwide, including the Callenberg mines in Saxony (Germany) and the Broken Hill area in New South Wales (Australia).

Rarity

Very rare

For collectors

## Quality Criteria The most highly prized iranite specimens are those with well-formed, distinct rosettes or radial aggregates of crystals with an intense, saffron-yellow color. Contrast with the rock matrix and the absence of damage to the delicate crystals are also important. Due to the microscopic size of the crystals, specimens are primarily evaluated under magnification. ## Popular Localities By far the most classic and valued specimens come from the type locality – the Sebarz mine in Iran. Material from this location is considered exemplary for the species.

Care and storage

## Cleaning Iranite specimens should be cleaned with the utmost care, preferably using compressed air to remove dust. Contact with water is not recommended, and if necessary, use a minimal amount of distilled water and a very soft brush, then immediately dry the specimen. Avoid ultrasonic cleaners. ## What to Avoid Absolutely avoid contact with acids and other chemicals that can damage the mineral. Iranite is soft and brittle, making it very susceptible to impacts and scratches. Protect it from high temperatures and sudden temperature changes. ## Storage Iranite specimens, due to their small size and fragility, should be stored in sealed, padded "micromount" boxes to protect them from mechanical damage and dust. Display should be away from direct sunlight and heat sources.

External references

Sources

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