Lamprophyres are a polygenetic group of rocks that have formed by the crystallization of common magma types, including lamproites and kimberlites, under volatile-rich conditions. The term lamprophyre is considered to have no genetic significance and the recognition of a lamprophyre facies is proposed as a means of conveying the concept that some members of a petrological clan crystallized under different conditions e.g. volatile-rich, to other members of that clan. A petrological clan is defined as suite of comagmatic rocks that have been derived from a particular parental magma which has been produced repeatedly in time and space. Lamprophyres are redefined as rocks which are characterized by the presence of euhedral-to-subhedral phenocrysts of mica and/or amphibole together with lesser clinopyroxene and/or melilite set in a groundmass which may consist (either singly or in various combinations) of plagioclase, alkali feldspar, feldspathoid, carbonate, monticellite, mica, amphibole, pyroxene, perovskite, Fe-Ti oxides and glass. The concept of a lamprophyre clan is considered to be unnecessary as it has no petrogenetic significance.