The Collaborative International Dictionary of English v.0.48:

Smaragdite \Sma*rag"dite\, n. [Cf. F. smaragdite; -- so called
   from its emerald-green color. See Smaragd.] (Min.)
   A green foliated kind of amphibole, observed in eclogite and
   some varietis of gabbro.
   [1913 Webster]