peridotite[per′ə dō′tīt′, pə rid′ə tīt′]
any of several coarsegrained, dark igneous rocks consisting mainly of olivine and other ferromagnesian minerals
Origin of peridotiteFrench péridotite ; from péridot, peridot
Any of various coarse-grained igneous rocks that consist mainly of olivine and pyroxene and are believed to be a main constituent of the earth's mantle.
From peridot +"Ž -ite.