The study of Middle Bronze Age pottery from Yassıtepe Höyük site in İzmir, Turkey, by FTIR and XRD with chemometrics

In this study, a combination of ATR-FTIR and XRD spectroscopy was used to characterize the mineralogical compositions and firing conditions of 108 Middle Bronze Age sherds collected from the different excavation areas of the Yassıtepe Höyük site in İzmir, Turkey. The FTIR results were processed using PCA and HCA to determine the similarities and correlations between the samples based on their mineralogical composition. PCA analysis employing second-derivative FTIR spectra (1700–400 cm−1) with 9 smoothing points classified the sherd samples into four main groups. The results provided from the FTIR analysis showed that all sherd groups have been fired at about 800–950 °C due to the simultaneous presence of the minerals of muscovite and Ca-silicate. Representative samples from the four main groups were analyzed by XRD, confirming FTIR results. Moreover, the findings show that FTIR analysis provides a very good tool for detecting different ceramic sherds as well as analyzing a large number of samples with low cost and fast analysis time.