sphal·er·ite 
(sfălə-rīt′)
(sfălə-rīt′)n.
The primary ore of zinc, occurring in usually yellow-brown or brownish-black crystals or cleavage masses, essentially ZnS with some cadmium, iron, and manganese. Also called blende, zinc blende.
[Greek sphaleros, slippery, deceitful (from its being easily mistaken for galena) (from sphallein, to trip, from sphalos, fetter, pair of stocks; akin to Sanskrit skhalate, he stumbles, and Armenian sxalem, I stumble) + -ITE1.]