- dunite
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/dooh"nuyt, dun"uyt/, n.a coarse-grained igneous rock composed almost entirely of olivine.[1865-70; named after Mt. Dun in New Zealand, where it is found; see -ITE1]
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Yellowish green to green igneous rock composed almost entirely of olivine.Chromite and magnetite also occur in dunite, as do spinel, ilmenite, pyrrhotite, and platinum in some cases. Dunites may be a source of chromium. Places of occurrence include Dun Mtn., New Zealand (the source of its name), South Africa, and Sweden.* * *
light yellowish green, intrusive igneous ultramafic rock that is composed almost entirely of olivine. Dunite usually forms sills (tabular bodies intruded between other rocks) but may also occur as lenses (thin-edged strata) or pipes (funnels, more or less oval in cross section, that become narrower with increasing depth). It is a common rock in Earth's upper mantle. Occurrences include Dun Mountain, New Zealand, from which the rock takes its name; the Bushveld Igneous Complex, South Africa; and Frostviken, Jämtland, Sweden. Chromite, picotite, and magnetite also occur in dunite, as do spinel, ilmenite, pyrrhotite, and platinum in some cases. Dunites constitute an important source of chromium, a commercially valuable metal.* * *
Universalium. 2010.
