Electronic Spectra of Minerals in the Visible and Near-Infrared Regions

A variety of features in the visible and near-infrared regions that are observed in remote sensing applications are the result of electronic transitions, typically involving cations of transition metals, most commonly Fe and Ti, or the molecular species S. The position and intensity of these features are sensitive not only to the particular cation, but also to its oxidation state, the particular phase in which it occurs, the geometric structure of the site that it occupies, and interactions between and among neighboring cations. Often these features are diagnostic for the host mineral.