Applications of Nuclear Analytical Techniques to Investigate the Authenticity of Art Objects

127 Nasca pottery and 10 imitations were analyzed by TL, NAA, XRF, TEM, DRX and Mossbauer spectroscopy to obtain analytical differences that allow differentiating them quickly. Additionally 20 pieces of the Wari culture found in the city of Cahuachi were analyzed. The multielementary composition of Nasca ceramics obtained by AAN allows, thanks to the multivariate analysis, differentiates the samples according to its geographic origin but we couldn't obtain a chronological classification. This indicates that Nasca pottery of each city was always prepared with the same raw material. However we can not classified samples from the Museum of the UNMSM, since these samples were collected in all Nazca regions. The brown, orange and yellow pigments of Nasca pottery contain different amounts of manganese and iron oxides. The same elements were found in modern ceramic, but additionally Pb and Zn were detected in the yellow color of the modern ones. The presence of illita in the paste of all the analyzed samples indicates that the firing temperature of Nasca pottery did not exceed 800 deg. C. Also, the fact that the quadrupole splitting in Mossbauer spectra as a function of temperature stays more or less constant until 700 deg. C and soon it falls quickly indicates that the firing temperature was approximately 700 deg. C. This was corroborated with the same analysis on samples from modern ceramic warmed up to approximate temperatures of 700 deg. C and 900 deg. C. (author)