The Collaborative International Dictionary of English v.0.48:

Olivine \Ol"i*vine\, n. [Cf. F. olivine.] (Min.)
   A common name of the yellowish green mineral chrysolite, esp.
   the variety found in eruptive rocks. It is a silicate of
   magnesium and iron ((Mg,Fe)SiO4).
   [1913 Webster +PJC]

The Collaborative International Dictionary of English v.0.48:

Chrysolite \Chrys"o*lite\, n. [L. chrysolithos, Gr. ?; chryso`s
   gold + ? stone: cf. F. chrysolithe.] (Min.)
   A mineral, composed of silica, magnesia, and iron, of a
   yellow to green color. It is common in certain volcanic
   rocks; -- called also olivine and peridot. Sometimes used
   as a gem. The name was also early used for yellow varieties
   of tourmaline and topaz.
   [1913 Webster]

WordNet (r) 3.0 (2006):

olivine
    n 1: a mineral consisting of magnesium iron silicate; a source
         of magnesium