uraninite
noun/jʊˈɹeɪnɪnaɪt/
Etymology From uran- + -ine + -ite.
1
Chemistry, Geography, Geology, Mineralogy, Natural sciences, Physical sciences Any of several brownish-black forms of uranium dioxide, UO₂, (especially pitchblende) that is the chief ore of uranium; it is isomorphous with thorianite.