Jáchymovite

jachymovite

uraninite

uranopilite

gypsum

Images

Formula: (UO₂)₈(SO₄)(OH)₁₄.13H₂O
or
(U₆₊O₂)₈(SO₄)(OH)₁₄.13H₂O
Hydrated sulphate, uranyl mineral
Crystal System: Monoclinic
Specific gravity: 4.79 calculated
Streak: Pale yellow
Colour: Yellow
Luminescence: Yellow under both SW and LW UV.
RADIOACTIVE
Environments

Hydrothermal environments

Localities

At the type locality, Jáchymov, Karlovy Vary District, Karlovy Vary Region, Czech Republic, jáchymovite occurs as acicular crystals, up to 0.1 mm long, that form centimetres-wide coatings. It is an oxidation product associated with gypsum, uranopilite and uraninite in dolomite-uraninite veins (AM 82.207-210).

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