noun. a dark coarse-grained igneous rock consisting principally of olivine.
- -ite (English)
- peridot (English)
- peridou (Anglo-Norman)
Example sentences of the word peridotite
1. Noun, singular or mass
The crust extends some 2 to 6 miles beneath ocean basins and as far as 50 miles beneath major mountain belts on the continent before transitioning to the iron- and magnesium-rich peridotite of the upper mantle.
The Peridot birthstone is produced from peridotite rock.