uraninite

American  

[yoo-ran-uh-nahyt, -rey-nuh-] / yʊˈræn əˌnaɪt, -ˈreɪ nə- /

noun

1. a mineral, probably originally uranium dioxide, UO 2 , but altered by radioactive decay, and usually containing uranium trioxide, lead, radium, and helium, occurring in several varieties, including pitchblende: the most important ore of uranium.

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uraninite British  

/ jʊˈrænɪˌnaɪt /

noun

1. a blackish heavy radioactive mineral consisting of uranium oxide in cubic crystalline form together with radium, lead, helium, etc: occurs in coarse granite. Formula: UO 2

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Etymology

Origin of uraninite

First recorded in 1875–80; uran(ium) + -in ² + -ite ¹