Natrouranospinite

natrouranospinite

uraninite

uranophane

metazeunerite

Images

Formula: Na2(UO2)2(AsO4)2.5H2O
Hydrated arsenate, uranyl mineral, meta-autunite group, forms pseudomorphs after metazeunerite (Dana)
Crystal System: Tetragonal
Specific gravity: 3.846 measured, 3.66 calculated
Hardness: 2½
Streak: Pale yellow
Colour: Lemon-yellow, straw-yellow, yellow-green
Luminescence: Fluoresces bright yellow green in SW and LW
Solubility: Natrouranospinite dissolves readily in dilute acids or in Na2CO3 solution (AM 43.383-384)
Common impurities: Ca
RADIOACTIVE
Environments

Hydrothermal environments

Localities

At the type locality, the Bota-Burum U deposit, Alakol, Almaty Region, Kazakhstan, Natrouranospinite occurs in fine, tabular to elongated crystals with lengths up to 2 cm, as radial fibrous aggregates, and as square crystals pseudomorphous after metazeunerite, sometimes with a core of metazeunerite. The natrouranospinite occurs in the oxidation zone of a primary hydrothermal uranium-sulphide deposit containing pitchblende, arsenopyrite, pyrite and galena in carbonatised granitic porphyry and tuffaceous breccia. Oxidation caused the formation of realgar, orpiment, scorodite, mansfieldite, metazeunerite, trögerite and arseniosiderite. Natrouranospinite is the most abundant secondary uranium mineral; it is sometimes replaced by uranophane (AM 43.383-384, as sodium uranospinite).

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