Raman and fluorescence

The most serious problem associated with conventional Raman spectroscopy is fluorescence and this is known as the Raman Achilles' heel. For minerals that exhibit even weak luminescence in the recorded spectral range, the Raman scattering will overlap partially or completely. The aim of this chapter is, on one hand, to present the various ways to get rid of fluorescence or at least to diminish its effect on the Raman spectrum, and on the other hand, to turn to advantage this phenomenon which has provided precious but often underexploited data. Gated Raman spectroscopy is developed and illustrated by examples as are excitation monitoring and polarization effects. The peculiar case of self-irradiated mineral phases and their healing, studied by complementary Raman and luminescence spectroscopies, is considered.