Ivory and simulated ivory artefacts: Fourier transform Raman diagnostic study

The Fourier transform Raman spectrum of ivory is reported and assignments are proposed for the major spectroscopic features. Application of the FT Raman technique to the non-destructive diagnostic identification of ivory and simulated ivory artefacts is illustrated with reference to several specimens, both modern and aged. Although the FT Raman spectrum of ivory is similar to that of other bone samples, the characteristic vibrational modes are identified and it is suggested that the relative intensity ratio of the nu(CH) stretching bands near 2930 cm(-1) and the hydroxyapatite nu(PO) stretching band at 960 cm(-1) is a good diagnostic parameter for ivory. Other modes, such as nu(NH) near 3300 cm(-1), the delta(CH2) profile near 1250 cm(-1) and nu(CC) symmetric ring stretching intensity at 1002 cm(-1) are also good confirming indicators to distinguish ivory from bone and synthetic specimens. Modern specimens of ''ivory'' using synthetic polymers and polymer-inorganic composites are easily distinguished spectroscopically from genuine ivory, particularly close textural specimens, which involved a synthetic blending of poly(methylmethacrylate), polystyrene and calcite.