Peridotite - rock from the Upper Mantle

This small hand sample (approx 3 cm) is very green, reflecting the colour of the abundant Olivine it contains.

Rock of the Earth's upper mantle, from under the ocean crusts, can be found in deep sea rifts and in ophiolites, where the ocean crust and mantle have been pushed up to the surface.

It formed in the mantle as the earth accreted on formation but also can form when Olivine and Pyroxene preciptate from ultramafic magmas.   Both Olivine and Pyroxene are found on the Moon