Seminar Maria-Cristina Caggiani

Raman spectroscopy is a versatile analytical technique, based on the interaction between light and matter, employed in many fields of application. The first information that can be obtained from a Raman spectrum concerns the nature of the chemical bonds and the symmetry of the vibrational units that constitute the molecule. Therefore, Raman spectroscopy is particularly appropriate to study both the chemical composition and the crystal structure of minerals.
Various examples of minerals investigation through Raman spectroscopy will be provided in this seminar, with different general aims, going from the gemmological characterization of precious gemstones, to more strictly minero-petrological issues that can give information about the solidification of lavas or about the processes of formation of the Earth.
More in detail, the Raman study of gem-quality tanzanite and corundum will be presented together with the determination of garnets composition. The diamond investigation will also be described, focusing not on gem-quality, but on deep-mantle diamonds containing multiphase inclusions, which were investigated in detail. Hints to minerals colour formation will be given with the in-depth study of blue haϋyne. Finally, the project in course in collaboration with CEMHTI and ISTO laboratories will be introduced, concerning the in-situ Raman analysis of lavas during their solidification.