The Collaborative International Dictionary of English v.0.48:

Jadeite \Jade"ite\, n. (Min.)
   See Jade, the stone.
   [1913 Webster]

WordNet (r) 3.0 (2006):

jadeite
    n 1: a hard green mineral consisting of sodium aluminum silicate
         in monoclinic crystalline form; a source of jade; found
         principally in Burma