[mass noun] A dense, coarse-grained plutonic rock containing a large amount of olivine, believed to be the main constituent of the earth's mantle.
- ‘The intellectual and creative processes by which we improve infrastructural code are no less natural than the geological forces that turn granite into gneiss, limestone into marble and peridotite into serpentine.’
- ‘Diamonds sometimes contain minute inclusions of the minerals garnet, olivine, and pyroxene, which indicate formation in two major mantle rock-types, peridotite and eclogite.’
- ‘Such rocks are important in defining ages for crustal rocks underlying the peridotite.’
- ‘The mantle is thought to be made up mostly of peridotite, a type of rock composed of iron, magnesium, silicon, and oxygen.’
- ‘The magma contains components of the sediments and weathered oceanic crust from the Nazca plate as well as the peridotite in the mantle beneath South America.’