Mineralogical analysis and firing temperature of the ancient potteries of Tamil Nadu using spectroscopic techniques

Abstract

Our curiosity about archaeological artefacts leads us to discover details about the lifestyles of our ancestors. Fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDX), and thermogravimetry differential thermal analysis (TG-DTA) techniques have been used to characterize the ancient potteries unearthed at the recently excavated archaeological site of Palayanur, Tamil Nadu. Minerals such as quartz (silicate group), feldspar, clay minerals (illite), calcite, hematite, magnetite, and organic carbon were identified from FT-IR analysis. Quartz had been detected in all of the samples, as evidenced by the significant absorption peaks at 794 cm−1, 795 cm−1, 779 cm−1, 780 cm−1, 781 cm−1, and 695 cm−1. The obtained 2θ values from the XRD spectrum validated the mineral’s presence as well as the pottery’s firing condition and temperature. The presence of calcite indicates that these samples were fired below 850 ℃, and the presence of hematite in the potteries indicates that they were fired in an oxidizing atmosphere. The elemental concentration and microstructure of collected pottery samples were determined by the SEM-EDX technique to elucidate the nature of the raw material used for making pottery samples.