ellsworthite

ellsworthite

[′elz·wər‚thīt]
(mineralogy)
(Ca,Na,U)2(Nb,Ta)2O6(O,OH) A yellow, brown, greenish or black mineral of the pyrochlore group occurring in isometric crystals and consisting of an oxide of niobium, titanium, and uranium. Also known as betafite; hatchettolite.
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