/sfal"euh ruyt', sfay"leuh-/ , n.
a very common mineral, zinc sulfide, ZnS, usually containing some iron and a little cadmium, occurring in yellow, brown, or black crystals or cleavable masses with resinous luster: the principal ore of zinc and cadmium; blackjack.
[ 1865-70; sphaler ( ós ) slippery, deceptive + -ITE 1 ]