jōˈhaˌnīt noun
( -s )
Etymology: German johannit, from Archduke Johann (John) of Austria died 1859 Austrian general, founder of a museum in Graz, Austria + German -it -ite
: a mineral Cu(UO 2 ) 2 (SO 4 )(OH) 2 .6H 2 O consisting of a green hydrous basic uranyl copper sulfate that occurs in massive form