Carlosruizite

Chemical formula: K<sub>3</sub>Na<sub>2</sub>Na<sub>3</sub>Mg<sub>5</sub>(I<sup>5+</sup>O<sub>3</sub>)<sub>6</sub>(Se<sup>6+</sup>O<sub>4</sub>)<sub>6</sub>·6H<sub>2</sub>O

Carlosruizite is an extremely rare potassium, sodium, and magnesium iodate-selenate, forming small, hexagonal crystals of an intensely orange color.

## Characteristics Carlosruizite is a complex hydrated iodate-selenate with an exceptionally complicated chemical composition, containing potassium, sodium, and magnesium. It occurs as very small, hexagonal, tabular or prismatic crystals, rarely exceeding 0.3 mm in size. These crystals often form rosette-like or spherical aggregates. Its most characteristic feature is an intense, bright orange color. ## Physical Properties This mineral is characterized by a hardness of approximately 3 on the Mohs scale. It has a vitreous luster. It is transparent to translucent. Due to the small size of the crystals, precise determination of density has been difficult, but the calculated value is 3.63 g/cm³. ## Colors and Varieties Carlosruizite occurs in a uniform, characteristic, bright orange color. No color varieties or commercial varieties are known. ## History and Name The mineral was discovered in the Corocoro mine in Pacajes Province, Bolivia. It was described and approved as a new mineral species by the IMA in 2014 (IMA2014-076). The name honors Carlos Ruiz Fuller (1916–1992), a Chilean geologist and founder of the Instituto de Investigaciones Geológicas in Chile, for his contributions to the understanding of the geology and mineral deposits of Chile. ## Uses Due to its extreme rarity and microscopic size, carlosruizite has no industrial applications. It is solely an object of scientific interest and a valuable acquisition for specialized collectors of rare minerals (so-called "micromounts").

Properties

Mohs hardness
3
Luster
Vitreous
Streak
Pale orange
Density
3.63
Cleavage
Perfect on {0001}
Fracture
Uneven
Transparency
Transparent to Translucent
Crystal system
Hexagonal

Diagnostic features

## Identification Carlosruizite is primarily recognized by its unique appearance: bright orange, hexagonal, tabular crystals forming small aggregates. However, identification requires advanced analytical methods, such as Raman spectroscopy or chemical analysis (EDS/WDS) to confirm its complex composition (presence of iodine, selenium, potassium, sodium, and magnesium). ## Distinguishing from Similar Minerals Based on color alone, it could be confused with other brightly colored secondary minerals. However, its characteristic hexagonal crystal form, specific occurrence environment (associations with other iodates), and extreme rarity allow for its differentiation. Certainty is only provided by chemical analysis. ## Crystal Forms It forms hexagonal, tabular crystals, often flattened parallel to the basal plane {0001}. It also occurs as short prisms. These crystals typically combine into rosette-like or spherical aggregates.

Geological environment

## Genesis Carlosruizite is a secondary mineral that forms in the oxidation zone of copper deposits under extremely arid (desert) climatic conditions. Its formation is associated with the weathering processes of primary selenium-bearing minerals, in the presence of iodate-rich solutions. ## Mineral Associations This mineral occurs in association with other rare iodates and selenates. In the type locality (Corocoro mine), it was found in association with gypsum, antofagastite, chalcomenite, as well as newly described minerals such as fuenzalidaite and leightonite. ## Localities The only confirmed locality of carlosruizite in the world is its type locality - the Corocoro copper mine, Coro Coro district, Pacajes Province, La Paz Department, Bolivia.

Rarity

Extremely rare

For collectors

## Quality Criteria The quality of carlosruizite specimens is primarily assessed based on the abundance and size of crystals on the rock matrix. The most desirable specimens are those with well-formed, undamaged, bright orange crystals or rich clusters thereof. Due to the microscopic nature of the mineral, the aesthetics of the entire sample and the contrast with surrounding minerals are also important. ## Popular Localities The only source of carlosruizite specimens is the Corocoro mine in Bolivia. All samples available on the collector's market originate from this single location.

Care and storage

## Cleaning Carlosruizite specimens are extremely small and delicate. Any mechanical cleaning should be avoided. If absolutely necessary, compressed air can be used from a safe distance to remove dust. Contact with water should be avoided, as the mineral may be soluble in it. ## What to Avoid Contact with water, acids, and other chemicals must be strictly avoided. The mineral is sensitive to changes in temperature and humidity. It should not be heated or exposed to direct sunlight, which can cause its degradation. ## Storage Specimens should be stored under stable conditions, preferably in sealed, lockable "micromount" boxes away from dust, humidity, and light sources. Due to its fragility, vibrations and shocks should be avoided.

External references

Sources

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