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.

PETROGRAPHIC REPORTS will include microscopic examination of thin sections with transmitted and reflected lights, detailed description of mineralogy and texture, classification of rocks where possible, visually estimated modal proportion of minerals, and description of primary and secondary minerals and their paragenetic sequence. In mineralized samples, the genesis of ore will be estimated. All reports will include 2 or more photomicrographs of each thin section taken by a digital Leica cooled camera, a cd with file(s) and 2 hard copies of the report.