peridotite

As a noun peridotite

is (geology|mineralogy) a rock consisting of small crystals of olivine, pyroxene and hornblende; the major constituent of the earth's mantle.

As an adjective undefined is

lacking a definition or value.

As nouns the difference between peridotite and pyroxenite

is that peridotite is a rock consisting of small crystals of olivine, pyroxene and hornblende; the major constituent of the Earth's mantle while pyroxenite is a heavy, dark igneous rock consisting mostly of pyroxene minerals with smaller amounts of olivine and hornblende.

As nouns the difference between peridotite and dunite

is that peridotite is a rock consisting of small crystals of olivine, pyroxene and hornblende; the major constituent of the Earth's mantle while dunite is a type of igneous rock with a coarse-grained or phaneritic texture.

As nouns the difference between taxonomy and peridotite

is that taxonomy is the science or the technique used to make a classification while peridotite is (geology|mineralogy) a rock consisting of small crystals of olivine, pyroxene and hornblende; the major constituent of the earth's mantle.

As nouns the difference between peridotite and kelyphite

is that peridotite is (geology|mineralogy) a rock consisting of small crystals of olivine, pyroxene and hornblende; the major constituent of the earth's mantle while kelyphite is (mineralogy) a substitution mineral found surrounding garnet in peridotites.