A rare earth mineral is a mineral that contains one or more rare earth elements as major metal constituents.Rare earth minerals are usually found in association with alkaline to peralkaline igneous complexes, in pegmatites associated with alkaline magmas and in or associated with carbonatite intrusives.Perovskite mineral phases are common hosts to rare earth elements within the alkaline complexes.are earth minerals are usually found in association with alkaline to peralkaline igneous complexes, in pegmatites associated with alkaline magmas and in or associated with carbonatite intrusives. Perovskite mineral phases are common hosts to rare earth elements within the alkaline complexes.