RRUFF PROJECT: DEVELOPING AN INTEGRATED DATABASE OF RAMAN AND INFRARED SPECTRA, X-RAY DIFFRACTION AND CHEMISTRY DATA FOR MINERALS

Raman spectroscopy was first documented in 1928 when Sir C.V. Raman wrote: "When a beam of monochromatic light is scattered by a transparent liquid, the scattered light contains frequency of very low intensity not present in the incident radiation." Although Raman's work was recognized for its direct application to the quantum theory of light, its usefulness as an identification tool was not realized until a suitable monochromatic light source (laser) was developed. Since the advent of lasers, Raman spectroscopy has been used extensively, but due to cost of equipment, the technology has been restricted to the research lab environment.

Seeing the potential of Raman as a versatile identification tool, our lab was funded by NASA to develop a miniature Raman device for the 2009 Mars rover. It was recognized that the miniaturization of the Raman spectrometer would make it suitable as a handheld device for use in identifying phases for homeland security, drug enforcement, gemstone identification etc. To support this device, the RRUFF project is assembling and maintaining an online database of every known mineral species, and an automated search match engine for search/match processing of spectral data.

Each RRUFF sample is screened to determine if the Raman spectra, is of sufficient quality for inclusion in the database. Samples are then run though a gambit of experiments including: X-ray powder diffraction (confirm identity), single crystal X-ray diffraction (orientation, and full crystal structure to elucidate cation site occupancies), electron microprobe analysis (determine chemistry), and Raman spectroscopy on oriented crystals. We will begin infrared spectroscopy experiments later this year.

Details for each sample including locality and photographs are posted with experimental data, free to access at: http://rruff.geo.arizona.edu/rruff/