An ultramafic rock consisting of major amounts of serpentinized olivine. It is associated with phlogopite, ortho- or clino-pyroxene, carbonates, and chromite. Pyrope garnet, rutile, and perovskite may also be present. Kimberlite is dark in color.

TEXTURE This is a coarse-grained rock, often with a porphyritic texture. Kimberlite can have a brecciated appearance.

ORIGIN Forms at the base of the Earth’s crust and is brought to the surface by steep-sided pipes. The pipes are usually less than a mile in diameter. Kimberlite pipes are the primary source of diamonds and are mined, especially in South Africa, for their high diamond content.

Group: IGNEOUS

Origin: Intrusive

Grain size: Coarse

Crystal shape: Euhedral

Classification: Ultramafic

Occurrence: Hypabyssal, Pluton

Color: Dark