Rare earth minerals occur predominantly in carbonatites, alkaline igneous complexes and paleoplacers. Light rare earth-element-rich (LREE) minerals are more common than the heavy and middle rare earth element rich variety. (HREE & MREE). In carbonatites, they are associated with calcite, Fe-rich carbonates, fluorite, aegirine and apatite. The Lofdal carbonatites in Namibia are oxidized and contain all of the above gangue minerals, whereas monazite, bastnaesite, parisite, synchysite, allanite, xenotime and aeschynite comprise the ore RE minerals. Alkali complexes such as the Strange Lake alkali complex are associated with aplite and contain an abundance of K and Na-feldspars, lesser aegirine, arfvedsonite and fluorite (Miller, 1996). Zr-silicates are common and gittinsite occurs in radiating clusters. In addition to the RE minerals, it contains also pyrochlore and thorite.

Identification of all rare earth minerals, distinction between primary and secondary phases, characterization of relevant gangue minerals and the host rock will be part of all Petrographic Reports. Some petrographic studies on REE deposits by GeoConsult include the Lofdal carbonatites in Namibia, South Africa, and the Stange Lake alkali complex in Quebec/Labrador, Canada.

Please visit GeoConsult Services for detailed information on Petrographic Reports