peridotite

Per"i*do*tite, n. Etym: [Cf. F. péridotite.] (Min.) Defn: 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.

---