Wildcatite

Chemical formula: CaFe<sup>3+</sup>Te<sup>6+</sup>O<sub>5</sub>(OH)

Wildcatite is an extremely rare calcium iron tellurate, discovered in the Wildcat Mine in Utah, USA.

## Characteristics Wildcatite is a microscopic mineral, forming very small, lath-like or platy crystals with dimensions not exceeding 150 micrometers. It typically occurs as radial or tangled aggregates. It is transparent to translucent, with a vitreous luster. ## Physical Properties Due to the microscopic size of its crystals, many physical properties, such as hardness, density, cleavage, or fracture, have not been precisely determined. The density calculated based on the formula and unit cell parameters is 4.83 g/cm³. ## Colors and Varieties This mineral is characterized by a pale, yellowish-green color. No varieties are known. ## History and Name Wildcatite was first described in 2022 by Anthony R. Kampf and his team. The name comes from the discovery locality – the Wildcat Mine in Tooele County, Utah, USA, which is its type locality. It was approved by the International Mineralogical Association (IMA) under number 2021-113. ## Uses Wildcatite has no industrial application and is solely an object of scientific and collecting interest for specialized micromineral collectors.

Properties

Luster
Vitreous
Streak
Pale yellow
Density
4.83
Cleavage
Perfect on {001}
Transparency
Transparent to translucent
Crystal system
Monoclinic

Diagnostic features

## Identification Identification of wildcatite is possible only through advanced analytical methods, such as Raman spectroscopy and single-crystal X-ray diffraction (XRD), combined with chemical analysis (EDS). Visually, it is characterized by pale yellowish-green, lath-like crystals forming radial aggregates. ## Differentiation from Similar Minerals It can be confused with other secondary, microscopic tellurates occurring in the same paragenesis, such as mcalpineite, frankhawthorneite, or utahyite. Certain differentiation requires specialized analytical equipment. ## Crystal Forms Wildcatite forms very small, lath-like crystals, elongated along the [010] axis and flattened parallel to {001}. These crystals combine into radial or randomly oriented aggregates.

Geological environment

## Genesis Wildcatite is a secondary mineral, forming in the oxidation zone (weathering) of ore deposits containing tellurium. At its type locality (Wildcat Mine), it formed as a result of the oxidation of primary tellurides within volcanic rocks (rhyolites). ## Mineral Associations This mineral coexists with other rare tellurates and tellurides. At the Wildcat Mine, it was found in association with mcalpineite, frankhawthorneite, quartz, barite, hematite, jarosite, emmonsite, tellurite, and utahyite. ## Localities The only confirmed occurrence of wildcatite in the world is its type locality: the Wildcat Mine, located in the Sheeprock Mountains, Tooele County, Utah, USA.

Rarity

Extremely rare

For collectors

## Quality Criteria As a micromineral, wildcatite is primarily evaluated based on the richness and aesthetics of crystal aggregates on the rock matrix. The most desirable specimens are those with well-formed, radial groups of crystals with an intense, yellowish-green color, clearly contrasting with the surrounding minerals. The presence of rare associated minerals is also important. ## Popular Localities The only source of wildcatite specimens is the Wildcat Mine in Utah, USA. Material from this locality is extremely limited and sought after by specialized micromineral collectors.

Care and storage

## Cleaning Wildcatite specimens are extremely delicate and small. Any mechanical cleaning should be avoided. If absolutely necessary, compressed air can be used from a safe distance to remove loose dust particles. ## What to Avoid Contact with any chemicals, acids, and bases should be avoided. It should not be heated or exposed to ultrasound. Due to its fragility, any shocks and vibrations should be avoided. ## Storage Specimens should be stored exclusively in specialized micromount boxes to protect them from mechanical damage, dust, and moisture. They should be kept under stable temperature conditions, away from direct sunlight.

Sources

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