ōˈtəˌnīt noun
( -s )
Etymology: Autun, Dept. Saône-et-Loire, France, its locality + English -ite
: a radioactive lemon-yellow mineral composed of uranyl calcium phosphate Ca(UO 2 )(PO 4 ) 2 .10−12H 2 O occurring in tabular crystals with basal cleavage and in micalike scales (sp. gr. 3.05-3.19)