Diversity of accessory minerals in rare-metal-rare earth pegmatites

About 150 accessory minerals have been identified in the rare-metal-rare earth pegmatites, including 36 OH-, F- and H₂ O-bearing silicates, 27 volatile-free silicates, 31 complex oxides, and 17 carbonates. Most accessories contain Y and Ce, and a few, certain other REEs. This diversity is a result of multistage postmagmatic autometasomatism and hydrothermal alteration. The elevated F, Y, La, Nb, Ta, Zr, U, and Th concentrations in parental alkali granites are also important, as well as differences between four mineragenic (geochemical) evolutional series of rare-metal-rare earth pegmatites.