| Noun | 1. | sphalerite - an ore that is the chief source of zinc; consists largely of zinc sulfide in crystalline formatomic number 81, thallium, Tl - a soft gray malleable metallic element that resembles tin but discolors on exposure to air; it is highly toxic and is used in rodent and insect poisons; occurs in zinc blende and some iron ores mineral - solid homogeneous inorganic substances occurring in nature having a definite chemical composition | |