Raman Spectroscopy and Forensic Mineralogy

Raman Spectroscopy is a non-destructive technique which provides detailed information about chemical structure, phase and polymorph, crystallinity and molecular interactions. It is a light scattering technique, in which a molecule scatters incident light from a high intensity laser light source. A Raman spectrum features a number of peaks, showing the intensity and wavelength position of the Raman scattered light. Each peak corresponds to a specific molecular bond vibration, including individual and groups of bonds. Typically, a Raman spectrum is a distinct chemical fingerprint for a particular molecule or material, and can be used to readily identify the material, or distinguish it from others, especially with the use of modern spectral libraries. Raman spectroscopy can be used to analyse many different materials, including solids, powders, liquids, gels, slurries and gases, inorganic, organic and biological materials, pure chemicals, mixtures and solutions. For these reasons, Raman techniques are used increasingly in forensic science fields to characterise gemstones, pigments, explosives and some dangerous materials.