GEOCHEMISTRY OF RARE EARTH ELEMENTS

Abstract Although called rare earths, elements lanthanum (atomic number 57) through lutetium (atomic number 71) on the periodic table, including yttrium (atomic number 37), are more common in nature than are many of the industrially important nonferrous metals. The rare-earth elements occur in oxide, silicate, phosphate, and carbonate compounds or as small fractions replacing calcium and strontium, whose ionic radii are similar to those of the rare-earth elements. Rare-earth minerals are more commonly found in pegmatites, granites, and nepheline syenites. Further study of the rare earths will aid geochemical prospecting, determination of mineralization processes, and clarification of geologic processes, as well as augmentation of alloy-metal reserves and product differentiation. Research International