Micro-Raman spectroscopy applied to the study of inclusions within sapphire

The present research concerns the characterization of samples of corundum (Al2O3), varieties of sapphire, by micro-Raman spectroscopy. Ten samples of natural corundum from Australia, Madagascar, Sri Lanka, Thailand, Tanzania, and Vietnam were studied. After standard gemmological analysis, micro-Raman analysis was also performed in order to identify mineral inclusions within the sapphire samples and to obtain information on the geological genres of the minerals. Several inclusions were evidenced within the sapphires and identified by Raman spectroscopy thanks to a confocal spectrometer, which allowed detection also below the external surface of the gem. Finally, the Raman spectra are discussed taking into account the provenance of the samples and their optical absorption. Copyright (c) 2008 John Wiley & Sons, Ltd.