Leu"co*phane (lū"k&osl;*fān), n. [Gr. leykofanh`s appearing bright or white; leyko`s white + fai`nein to show: cf. G. leukophan.] (Min.) A mineral of a greenish yellow color; it is a silicate of glucina, lime, and soda with fluorine. Called also leucophanite.