Kamitugaite

Chemical formula: Pb<sup>2+</sup>Al(U<sup>6+</sup>O<sub>2</sub>)<sub>5</sub>(PO<sub>4</sub>)<sub>3</sub>O<sub>2</sub>(OH)<sub>2</sub>(H<sub>2</sub>O)<sub>11.5</sub>

Kamitugaite is a very rare, bright yellow secondary uranium mineral, found in the oxidation zones of uraninite deposits.

## Characteristics Kamitugaite is a hydrated phosphate of lead, aluminum, and uranyl. It forms very small, tabular or bladed crystals, rarely exceeding 1 mm in length. They typically occur as radial aggregates, rosettes, or coatings on other minerals. Its most characteristic feature is its intense, bright yellow to yellowish-green color. ## Physical Properties Kamitugaite crystals exhibit a vitreous luster. The mineral is transparent to translucent. Due to the small size of the crystals, precise determination of hardness and density is difficult; however, its hardness is estimated to be around 4 on the Mohs scale, and its calculated density is 4.47 g/cm³. ## Colors and Varieties This mineral occurs in shades from bright yellow to greenish-yellow. No varieties have been distinguished. ## History and Name Kamitugaite was first described in 1984 by Michel Deliens and Paul Piret. Its name comes from its discovery locality – the Kobokobo uranium mine in the Kamituga region, South Kivu Province, Democratic Republic of Congo. This is the only known occurrence of this mineral in the world. ## Uses Due to its extreme rarity and small size, kamitugaite has no industrial applications. It is solely an object of interest for collectors specializing in uranium minerals and rare mineral species.

Properties

Mohs hardness
4
Luster
Vitreous
Streak
Light yellow
Density
4.47
Cleavage
Perfect on {100}
Fracture
Uneven
Transparency
Transparent to translucent
Crystal system
Triclinic

Diagnostic features

## Identification Key diagnostic features of kamitugaite include its intensely bright yellow color, characteristic radial aggregates of small, bladed crystals, and occurrence in association with other secondary uranium minerals. Strong fluorescence under ultraviolet light (both shortwave and longwave) is also an important indicator. However, definitive confirmation requires advanced analytical methods, such as X-ray diffraction (XRD). ## Distinguishing from Similar Minerals Kamitugaite can be confused with many other yellow secondary uranium minerals, such as autunite, torbernite (in meta-form), uranophane, or studtite. Distinguishing it based on visual characteristics alone is extremely difficult and often impossible without chemical or crystallographic analysis. Analysis of the mineral association and crystal habit can be helpful, but only laboratory testing provides certainty. ## Crystal Forms Kamitugaite forms thin, tabular or bladed crystals, elongated in one direction. They most commonly occur as radial or stellate aggregates and rosettes, as well as crusts and coatings.

Geological environment

## Genesis Kamitugaite is a secondary mineral, formed in the oxidation (weathering) zone of granitic pegmatites containing uraninite. It forms through complex hydrothermal processes, where groundwater rich in phosphorus and other elements reacts with primary uranium ores. ## Mineral Associations This mineral occurs in association with other secondary uranium minerals. It most commonly co-occurs with dumontite, phosphuranylite, meta-autunite, metatorbernite, saleeite, as well as with quartz, muscovite, and tourmaline, which are components of the host rock (pegmatite). ## Localities The only confirmed and described locality for kamitugaite in the world is its type locality – the Kobokobo pegmatite in the Kamituga region, South Kivu Province, Democratic Republic of Congo.

Rarity

Extremely rare

For collectors

## Quality Criteria The collector appeal of kamitugaite primarily depends on the quality and size of the crystal aggregates. Most valued are specimens with well-formed, radial rosettes of intense, bright yellow color, contrasting with the darker host rock. A rich association with other rare uranium minerals from the same locality is also important. Due to the microscopic size of the crystals, even small but distinct clusters are considered valuable. ## Popular Localities The only source of kamitugaite specimens is the Kobokobo mine in the Democratic Republic of Congo. All specimens available on the collector's market originate from this single location, making them extremely sought after by specialists in systematic minerals and uranium minerals.

Care and storage

## Cleaning Kamitugaite specimens should generally not be cleaned mechanically or chemically. Due to its fragility and the small size of its crystals, any attempt at cleaning risks irreversible damage. If absolutely necessary, compressed air (from a safe distance) can be used to remove loose dust particles. ## What to Avoid As a uranium mineral, kamitugaite is radioactive and should be handled with appropriate precautions. Direct, prolonged skin contact should be avoided, and above all, inhalation of dust that might arise from damaging the specimen. It should be protected from moisture, chemicals, and high temperatures. ## Storage Kamitugaite specimens should be stored in closed, airtight containers (e.g., "perky boxes"), clearly labeled as radioactive material. They should be kept away from other radiation-sensitive minerals (e.g., smoky quartz, some fluorites), and also away from areas of permanent human habitation, especially bedrooms and living rooms.

Sources

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