Differentiation of antique ceramics from the Raman spectra of their coloured glazes and paintings

Two palettes, characteristic of the production of the Sevres Factory (Manufacture Nationale de Sevres), and representative of ancient glazing techniques, were studied. One was made with coloured glazes/enamels on Bisque (1050 degreesC) and the other one was composed of Moufle (880 degreesC) painting colours. Spectra specific to the white (opacifiers), yellow (including Naples yellow), green, pink,'brown-red' and black coatings/paintings were considered. Emphasis was placed on the different Raman peaks arising from coloured coatings specific to ancient artefacts: greens obtained with dissolved Cu ions or from chromium pigments I:Victoria green garnets), Naples yellows (Pb2Sb2O7 pyrochlore), green and black spinels and pink sphene. Attention was paid to the effect of pigment grain size on the Raman spectrum. To illustrate the capability of the method, we analysed some old artefacts from the eighteenth and nineteenth centuries. Copyright (C) 2001 John Wiley & Sons, Ltd.