Kimberlite is an ultramafic rock which contains diamonds. It gets its name from the township of Kimberley in South Africa, where diamonds were discovered. Kimberlite is a breccia mica peridotite that is dark green or grey and is composed of minerals such as forsterite, phlogopite and pyrope. It often contains xenoliths that come from the mantle, deep crust or shallow country rocks. It often appears in a volcanic pipe, volcanic neck dyke or vein. Since diamonds are usually found in association with kimberlites, this rock has received much attention. In China, diamonds are mined in kimberlites in Liaoning and Shandong Provinces.