Peridotite

A dense green rock of olivine and pyroxene — the main rock of Earth's upper mantle.

Peridotite specimen — Photo: Shannon Heinle, CC0, via Wikimedia Commons

How to identify peridotite

Green, coarse and very heavy.
Mostly glassy olivine grains.
Weathers to a rusty brown crust.

Often confused with

Dunite
Dunite is almost all olivine.
Compare side by side
Serpentinite
Serpentinite is altered peridotite: waxy and slick.
Compare side by side

Where it's found

Samail ophiolite, Oman
Tablelands, Newfoundland
San Carlos, Arizona (xenoliths)

Uses

Research on the mantle; studied for capturing CO₂.

Rock tumbling

Can be tumbled with care.

Did you know?

In Newfoundland's Tablelands you can walk on mantle rock pushed up to the surface.

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