Camaronesite

Chemical formula: Fe<sup>3+</sup><sub>2</sub>(PO<sub>3</sub>OH)<sub>2</sub>(S<sup>6+</sup>O<sub>4</sub>)(H<sub>2</sub>O)<sub>4</sub>·1-2H<sub>2</sub>O

Camaronesite is a very rare, hydrated iron sulfate-phosphate, forming characteristic, platy crystals of an intense, yellow-orange color.

## Characteristics Camaronesite is a secondary mineral from the phosphate and sulfate groups. It occurs as very small, thin, platy or bladed crystals, which often form fan-like or rosette-shaped clusters and aggregates. Its most characteristic feature is its intense, bright color, ranging from golden-yellow to orange-yellow. The crystals are usually transparent and exhibit a strong, vitreous luster. ## Physical Properties It is a very soft mineral, with a hardness of only 2 on the Mohs scale. Its crystals are brittle and delicate. The calculated density is approximately 2.61 g/cm³. It exhibits perfect cleavage in one direction. ## Colors and Varieties This mineral does not form color varieties or commercial forms. Its color is constant and falls within the spectrum from bright yellow to orange-yellow. Color is one of its main visual attributes. ## History and Name Camaronesite was described as a new mineral in 2010 by a team of mineralogists led by Stuart J. Mills. Its name comes from the discovery locality - the Camarones mining district in the Arica y Parinacota region in northern Chile. This is the only confirmed occurrence of this mineral in the world. ## Applications Due to its extreme rarity and occurrence as microscopic crystals, camaronesite has no industrial applications. It is solely an object of scientific interest and is valued by specialized collectors of rare minerals.

Properties

Mohs hardness
2
Luster
Vitreous
Streak
Pale yellow
Density
2.61
Cleavage
Perfect on {010}
Fracture
Uneven
Transparency
Transparent to translucent
Crystal system
Triclinic

Diagnostic features

## Identification Key diagnostic features of camaronesite are its unique crystal habit - thin, platy forms creating rosettes and fans - combined with a bright, yellow-orange color and vitreous luster. Its origin from the only known locality and co-occurrence with other secondary iron phosphates and sulfates are also characteristic. ## Distinguishing from Similar Minerals Camaronesite can be confused with other yellow secondary minerals: - **Jarosite**: Usually forms smaller, trigonal crystals or occurs as earthy coatings and has a more dull luster. - **Beraunite**: Often has a more reddish or brownish hue and forms aggregates of a different habit, rarely platy rosettes. - **Strengite (yellow variety)**: Has a different crystal form (usually spherulitic or radial aggregates) and does not contain sulfates. ## Crystal Forms Crystals are thin, platy, flattened parallel to {010} and often elongated. They most commonly occur as radial or rosette-shaped aggregates, where individual crystals radiate from a common center.

Geological environment

## Genesis Camaronesite is a secondary mineral, formed in the oxidation zones (gossans) of polymetallic deposits in an arid climate. Its formation is a result of the weathering of primary iron minerals (e.g., pyrite) and phosphorus (e.g., apatite) under the influence of acidic, sulfate-rich waters. ## Mineral Associations This mineral occurs in association with other secondary iron phosphates and sulfates. The most common associated minerals include strengite, beraunite, leucophosphite, jarosite, and goethite. ## Localities The only confirmed and described occurrence of camaronesite in the world is its type locality - the María Elena mine, located in the Camarones mining district, in the Arica y Parinacota region of Chile.

Rarity

Very rare

For collectors

## Quality Criteria The quality of camaronesite specimens, which are typically micromounts, is assessed based on several criteria. Specimens with well-formed, sharp, and undamaged crystals forming aesthetic, rosette-shaped aggregates are most highly valued. The intensity and purity of the yellow-orange color also significantly increase value. A contrasting matrix or association with other rare minerals adds to its appeal. ## Popular Localities All specimens available on the collector's market come from a single location in the world - the María Elena mine in Chile. This is the sole source of this mineral.

Care and storage

## Cleaning Camaronesite specimens are extremely delicate and brittle. To remove dust, use only compressed air from a safe distance or a very soft, dry brush. Avoid contact with water, as it can affect the hydrated structure of the mineral. ## What to Avoid Absolutely avoid ultrasonic cleaners, any chemicals, detergents, and contact with water. The mineral is very soft, so it must be protected from impacts and scratches. Also avoid exposure to high temperatures, which can lead to dehydration and destruction of the crystals. ## Storage It is recommended to store specimens in closed, padded "micromount" boxes, which protect against dust, moisture, and mechanical damage. Store in stable temperature conditions, away from direct sunlight.

Sources

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