Vanadium is considered by many to be the most difficult element to characterize geochemically because of its low crustal abundance and its existence in three valence states under geologic conditions. Vanadium minerals are typically poorly-crystallized, and its isolation of samples suitable for crystal structure studies has historically proved difficult; thus, our knowledge of the crystal-chemical behavior of vanadium has not kept pace with other mineral groups. The research proposed will produce crystal structure solutions or refinements of several vanadium minerals and related minerals. The first will be the lead apatites, the second brackebuschite and gamagarite, and the final portion of the project will be the determination of the crystal structure of ziesite, a high-temperature vanadium mineral.
