Author name: Peter R. Buseck

This article reviews nonconventional Raman spectroscopy techniques and discusses present and future applications of these techniques in the Earth and planetary sciences. Time-resolved spectroscopy opens new ways to limit or exploit luminescence effects, whereas techniques based on coherent anti-Stokes Raman scattering (CARS) or surface-enhanced Raman spectroscopy (SERS) allow the Raman signal to be considerably enhanced even down to very high spatial resolutions. In addition, compact portable Raman spectrometers are now routinely used out of the laboratory and are even integrated to two rovers going to Mars in the near future.

Geoscientists quickly recognized the broad applicability of Raman microprobe spectroscopy to the Earth and planetary sciences, especially after commercially built microprobe instruments became available in the early 1980s. Raman spectra are sensitive to even minor (chemical or structural) perturbations within chemical bonds in (even amorphous) solids, liquids, and gases and can, thus, help identify, characterize, and differentiate between individual minerals, fluid inclusions, glasses, carbonaceous materials, solid solution phases, strain in minerals, and dissolved species in multi-component solutions. The articles in this issue explore how Raman spectroscopy has deepened and broadened our understanding of geological and extraterrestrial materials and processes.