Optical spectra are
concerned with the
quantitative measurement of the
absorption, reflection and emission of
light in the near-ultraviolet (~250 nm) through the mid-infrared (~3000 nm) portions of
the
spectrum. The reflection spectroscopy of minerals
has been motivated largely by interest in
remote sensing. Studies
of
metal ion site occupancy, oxidation states and concentrations have
generally
been done with absorption spectroscopy.
This chapter will concentrate on single crystal absorption
spectroscopy.