Raman spectra of mammoth ivory specimens have been recorded using near-infrared excitation, and comparisons made with modern Asian and African elephant ivories. Whereas the most ancient mammoth ivory (60-65 ky) showed no evidence for an organic collagen component, more recent samples of mammoth ivory indicated that some preservation had occurred, although with biodeterioration of the protein structure exhibited by the amide I and III bands in the 1200-1700 cm(-1) region of the Raman spectrum. The consequent difficulties encountered when applying chemometrics methods to ancient ivory analysis (which are successful for modern specimens) are noted. In the most ancient mammoth ivory specimens, which are extensively fragmented, evidence of mineralization is seen, with the production of gypsum, calcite and limonite; Raman microscopic analysis of crystalline material inside the fissures of the mammoth ivory shows the presence of gypsum as well as cyanobacterial colonisation. The application of Raman spectroscopy to the nondestructive analysis of archaeological materials in order to gain information of relevance to their preservation or restoration is highlighted.

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Specimens of mammoth, African and Asian ivory dentine, and other mammalian species were examined using Fourier-Transform (FT), conventional dispersive (confocal) and remote-sensing portable Raman spectroscopy, all with near-infrared laser excitation (1064 and 785 nm). FT-Raman spectroscopy produced the best quality spectra for differentiation purposes and the application of a fibre probe coupled to a portable Raman spectrometer has also been demonstrated and proposed for the in situ characterization of suspected contraband ivories at airports. In addition to the visual comparison of spectral features, chemometric methods are used to discriminate between African and Asian elephant dentine by analyzing normalized integrated band areas in ten selected wavenumber regions. Principal component analysis separates the spectra of both species into two well-defined groups based upon their organic and inorganic composition. By means of stepwise discriminant analysis almost 98% of the spectra are correctly classified to their species group memberships.

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