On-site Raman spectroscopic analysis of Kutahya fritwares

On-site Raman analyses were performed at the Musee National de Ceramique, Sevres, France, on Kutahya pottery. A comparison was made with Iznik and Safavid productions. Two Raman signatures of silicate glazes (with an index of polymerization similar to 0.6-1 indicating a lead silicate composition, with characteristic Si-O stretching doublet at similar to 985 and 1050 cm(-1)) were recognized and associated with the colour. Considering the peak position and the ratios of Q(n) (n = 1, 2 and 3) components allows the classification of the different productions. Differentiation between Kutahya and Iznik Ottoman pottery is straightforward from the centres of gravity. The procedure is also efficient for discriminating between early and late Iznik production. The white colour arises from a a-quartz slip. Although Iznik production does not fluctuate, as a consequence of the nakkashame regulation, the composition/nanostructure dispersion of Kutahya wares is large and different families can be recognized. The non-stoichiometric character of the spinel-type materials used to draw the black lines appears to be at the origin of the sharpness of the depicted figures. Copyright (c) 2005 John Wiley & Sons, Ltd.