Cloncurryite

Chemical formula: Cu<sup>2+</sup><sub>0.5</sub>(V<sup>4+</sup>O)<sub>0.5</sub>Al<sub>2</sub>(PO<sub>4</sub>)<sub>2</sub>F<sub>2</sub>·5H<sub>2</sub>O

Klonkurryite is a very rare, secondary phosphate mineral with a characteristic blue color, found as microscopic aggregates.

## Characteristics Klonkurryite is a hydrated aluminum, vanadium, and copper phosphate, belonging to the wallkillskite group. It occurs as very small, spherical aggregates or rosettes composed of tabular crystals, reaching sizes up to 0.2 mm. Its most characteristic feature is its intense, blue color. ## Physical Properties Klonkurryite crystals exhibit a vitreous luster. Due to the microscopic size of the crystals, most physical properties, such as hardness or density, have not been precisely determined. The mineral is transparent to translucent. ## Colors and Varieties This mineral occurs in a uniform, bright, blue color. No varieties have been distinguished. ## History and Name The name klonkurryite comes from its discovery locality – the Great Australia mine in the Cloncurry region of Queensland, Australia. It was described and approved as a new mineral by the International Mineralogical Association (IMA) in 2017 (IMA2017-028).

Properties

Luster
Vitreous
Streak
Light blue
Cleavage
Perfect on {0001}
Fracture
Micaceous
Transparency
Transparent to translucent
Crystal system
Trigonal

Diagnostic features

## Identification Klonkurryite can be identified by its unique blue color, its occurrence as small, spherical aggregates, and its association with other rare secondary minerals such as turquoise, pseudomalachite, or libethenite. ## Distinguishing from Similar Minerals It can be confused with other blue secondary minerals, such as turquoise or chalcanthite. It differs from turquoise by its generally more radial aggregate structure. Unlike water-soluble chalcanthite, klonkurryite is stable in contact with atmospheric moisture. However, certain identification requires advanced analytical methods (XRD, EDS). ## Crystal Forms It forms spherical or hemispherical aggregates and rosettes, which consist of very small, thin, tabular crystals. Individual crystals are usually too small to be observed without magnification.

Geological environment

## Genesis It is a secondary mineral, forming in the oxidation zone of copper deposits. It forms in voids and fissures in rocks rich in phosphorus and aluminum, as a result of the weathering of primary ore minerals in an arid climate. ## Mineral Associations It most commonly co-occurs with turquoise, pseudomalachite, libethenite, quartz, goethite, and minerals from the alunite group. ## Localities The only confirmed locality of klonkurryite in the world is its type locality – the Great Australia mine, Cloncurry, Queensland, Australia.

Rarity

Extremely rare

For collectors

## Quality Criteria The most highly valued specimens are those with well-formed, spherical aggregates of intense blue color, contrasting with the rock matrix. Due to the microscopic nature of the mineral, the size of the aggregates (even if measured in fractions of a millimeter) and their abundance on the specimen's surface significantly increase its collector's value.

Care and storage

## Cleaning Specimens should only be cleaned with compressed air to remove dust. Due to the extreme delicacy and small size of the crystals, any other method, including the use of water or soft brushes, risks irreversible damage to the aggregates. ## What to Avoid Avoid contact with water, chemicals, ultrasound, and any vibrations or impacts. Do not expose specimens to high temperatures, which can lead to dehydration and destruction of the mineral's structure. ## Storage Klonkurryite specimens require storage under stable conditions, preferably in tightly sealed "micromount" boxes, which protect them from dust, moisture, and mechanical damage. Avoid exposure to direct sunlight.

Sources

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