OPAL - AN OVERVIEW

Host rocks within a mantle keel contain harzburgite and lherzolite, two kind of peridotite. Essentially the most dominant rock type in the higher mantle, peridotite is undoubtedly an igneous rock consisting primarily from the minerals olivine and pyroxene; it can be small in silica and higher in magnesium.Impurities in all-natural diamonds are beca