Eclogite

“Jewels from the mantle”

Metamorphic

Eclogite is a spectacular, dense metamorphic rock that forms under extreme pressures at depths greater than 45 kilometers. Its striking appearance — red garnets embedded in bright green pyroxene — makes it one of the most beautiful rocks found on Earth.

Composition

garnet (pyrope-rich), omphacite (green pyroxene), rutile, kyanite

Where Found

Norway, Western Alps, Dabie Shan (China), Franciscan Complex (California, USA)

Mohs Hardness

6-7

Fun Fact

Eclogite is so dense that when large slabs of it form in subducting oceanic crust, they help pull tectonic plates down into the mantle like an anchor.