This is a mantle xenolith - a piece of the Earth’s mantle that has managed to separate into upper layers of rock and reach the surface (usually via volcanic activity or ophiolitic uplift). The xenolith is composed of olivine, and is set here in a basaltic matrix. This sample comes from Tenerife.

This is a mantle xenolith - a piece of the Earth’s mantle that has managed to separate into upper layers of rock and reach the surface (usually via volcanic activity or ophiolitic uplift). The xenolith is composed of olivine, and is set here in a basaltic matrix. This sample comes from Tenerife.