Ewingite

ewingite

uraninite

metazellerite

gypsum

Images

Formula: Mg₈Ca₈(UO₂)24(CO₃)₃₀O₄(OH)₁₂(H₂O)₁₃₈
Carbonate, uranyl mineral, the most structurally complex mineral discovered to date (November 2024) (Mindat)
Crystal System: Tetragonal
Specific gravity: 2.525 calculated
Hardness: ~2
Streak: Pale yellow
Colour: Golden yellow
RADIOACTIVE
Environments

Hydrothermal environments

Ewingite is a relatively new mineral, approved in 2016; to date (November 2024) the only confirmed localities are the type localities

Localities

There are rwo co-type localities, the Svornost Mine, Jáchymov, and the Plavno mine, Hanušov, Ostrov, both in the Karlovy Vary District, Karlovy Vary Region, Czech Republic. At the Plavno mine, Hanušov, Ostrov, Karlovy Vary District, Karlovy Vary Region, Czech Republic, ewingite occurs as a secondary mineral formed by postmining oxidation of primary uraninite, in a wet environment on a damp wall in an abandoned underground mine. Associated minerals include liebigite, metazellerite, gypsum and uraninite (HOM).
Ewingite forms aggregates of golden-yellow crystals as large as 0.2 mm across (Mindat).
Ewingite from the Plavno Mine - Image

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