\Per"i*do*tite\, n. [Cf. F. p['e]ridotite.] (Min.)
An eruptive rock characterized by the presence of chrysolite
(peridot). It also usually contains pyroxene, enstatite,
chromite, etc. It is often altered to serpentine.

Note: The chief diamond deposits in South Africa occur in a
      more or less altered peridotite.