The calcium phosphate apatites are found in igneous, metamorphic, and sedimentary rocks. Interest among geologists in these minerals has increased in recent years, especially as indicators of geologic environment. Recent investigations by the P.I.'s indicate that many aspects of the crystal structures of natural apatites are not well understood. The studies proposed are intended to elucidate the crystal structures of natural apatites. They will emphasize naturally-occurring apatites, whose chemistry falls within ranges of interest to geologists, and the resultant data will complement that already available in the published literature. The proposed research should be important to geologists who use thermodynamics, partitioning, diffusion and annealing properties of apatite minerals to gain insight into geologic processes.
