ˈävə̇dsəˌnīt noun
( -s )
Etymology: J.A. Arfvedson died 1841 Swedish chemist + English -ite
: a silicate of sodium, calcium, and iron, approximately Na 2-3 (Fe,Mg,Al) 5 Si 8 O 22 (OH) 2 , of the amphibole group occurring in black monoclinic strongly pleochroic prisms in certain igneous rocks