Wiperamingaite

Chemical formula: NaCaFe<sup>3+</sup>Al(PO<sub>4</sub>)F<sub>5</sub>(OH)·H<sub>2</sub>O

An extremely rare phosphate mineral, discovered in Australia, with a complex chemical composition.

## Characteristics Wiperamingaite is a complex hydrated fluophosphate of sodium, calcium, iron, and aluminum. It forms very small, acicular or lath-like crystals, which typically occur as radial or tangled aggregates. Individual crystals rarely exceed 0.1 mm in length, making this mineral of interest primarily in the world of micromineralogy. Its color ranges from pale to reddish-brown. ## Physical Properties The crystals are transparent and exhibit a vitreous luster. Due to the microscopic size and fragility of the crystals, its Mohs hardness and fracture characteristics could not be determined. The density calculated based on the chemical composition and unit cell parameters is 3.16 g/cm³. ## Colors and Varieties This mineral occurs in shades of brown – from light, pale yellow-browns to more intense, reddish-browns. No color varieties or commercial names have been distinguished. ## History and Name It was officially recognized by the International Mineralogical Association (IMA) in 2017. Its name comes from the discovery locality – the Wiperaminga kimberlite pipe in South Australia. It was described by a team of mineralogists: P. Elliott, G. Giester, U. Kolitsch, and U. Witzke in a publication in "Mineralogical Magazine" in 2018. ## Applications Due to its extreme rarity and microscopic size, wiperamingaite has no practical applications. It serves solely as an object of scientific research and a valuable specimen in advanced systematic and micromineralogical collections.

Properties

Luster
Vitreous
Streak
White
Density
3.16
Transparency
Transparent
Crystal system
Monoclinic

Diagnostic features

## Identification Identification of wiperamingaite based on visual characteristics is impossible, even under a microscope. The only reliable method is advanced chemical analysis (e.g., EDS/WDS) to confirm the complex composition and X-ray diffraction (XRD) analysis to verify the crystal structure. ## Distinguishing from Similar Minerals It can be confused with other fine-grained, brown secondary minerals occurring in similar environments. Differentiation requires specialized analytical equipment. ## Crystal Forms It forms elongated, acicular or lath-like crystals. They usually occur as small, radial or haphazardly tangled aggregates in rock cavities.

Geological environment

## Genesis Wiperamingaite is a hydrothermal mineral. It forms during the late stage of crystallization at low temperatures, filling small voids (fissures and vugs) within kimberlite rocks. ## Mineral Associations At the type locality, it co-occurs with minerals such as apatite, phlogopite, and an unidentified magnesium-aluminum silicate. ## Localities The only confirmed occurrence of this mineral in the world is its type locality – the Wiperaminga kimberlite pipe, located near the town of Terowie in South Australia.

Rarity

Extremely rare

For collectors

## Quality Criteria For micromineral collectors, the most important criterion is the richness of the specimen, i.e., the quantity and quality of well-formed crystal aggregates on the rock matrix. The aesthetics of the entire cluster and confirmation of the mineral's identification by a laboratory or reputable specialist are also important. The size of the crystals, even if sub-millimeter, also increases the value of the specimen. ## Popular Localities The only source of specimens is the type locality in South Australia. Material from this location is extremely difficult to acquire and is only available through a narrow specialized circuit.

Care and storage

## Cleaning Any attempts at mechanical or chemical cleaning are absolutely inadvisable. Specimens are microscopic and extremely fragile, and any intervention risks irreversible destruction of the crystals. ## What to Avoid Avoid touching, vibrations, ultrasound, all liquids, and chemical agents. The mineral is stable under normal conditions, but its physical integrity is very low. ## Storage Wiperamingaite specimens should be stored exclusively in specialized "micromount" boxes, which protect them from dust, shocks, and mechanical damage. Display is only possible under a microscope.

Sources

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