Definition of "dunite" []

• A dense igneous rock that consists mainly of olivine and is a source of magnesium. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "C peridotite and dunite the upper mantle is composed of ultramafic rock called peridotite which is mostly olivines and pyroxenes."
• "The Ural Mountain deposits of Russia are gold - and platinum-bearing placers, in streams which drain areas of dunite rock containing minute quantities of native platinum."
• "The zones are separated by a horizon of disseminated chromite hosted within peridotite and dunite."