Metastudtite

metastudtite

uraninite

uranophane

soddyite

Images

Formula: UO4.2H2O
Oxide
Crystal System: Orthorhombic
Specific gravity: 4.67 calculated
Streak: Light yellow
Colour: Light yellow
Solubility: Soluble in hot hydrochloric acid
RADIOACTIVE
Environments

Sedimentary environments
Hydrothermal environments

Metastudtite is an extremely rare secondary mineral, formed by dehydration of studtite and found on museum specimens of dolomite and uraninite, from the oxidised zone of a uranium deposit. It contains a peroxide group (O2)2- in its crystal structure. Associated minerals include uraninite, uranophane, soddyite, uranopilite, fourmarierite, wolsendorfite, rutherfordine, becquerelite, masuyite and kasolite (HOM).

Localities

At the type locality, the Shinkolobwe Mine, Shinkolobwe, Kambove District, Haut-Katanga, DR Congo, metastudtite was found in two samples.
The first sample is a grey brecciated and deeply altered dolostone. The surface is almost completely covered with a coating in which the following minerals have been identified: grey fibres of rutherfordine, prismatic tablets of amber yellow becquerelite, red pseudohexagonal crystals of masuyite, red-orange short crystals of kasolite and red microcrystals of wölsendorfite; two small radiated nodules of metastudtite, about 1.2 mm in diameter, occur on the wölsendorfite.
The second sample is a massive block of purple black uraninite, with one face covered with a yellow coating mainly composed of needles of uranophane and short crystals of soddyite. A few aggregates of silky, pale yellow fibres of metastudtite up to 3 mm in length are mixed with the uranophane. A few orange nodules of kasolite and powdered yellow uranopilite complete the association (AM 68.456-458).

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