/hyooh"leuhn duyt'/ , n.
a white or transparent, colorless mineral of the zeolite family, hydrous calcium aluminum silicate, CaAl 2 Si 7 O 18 ·6H 2 O, occurring in basic volcanic rocks in the form of crystals with a pearly luster.
[ 1815-25; named after Henry Heuland, 19th-century English mineral collector; see -ITE 1 ]