Ochre and other pigments from the 7th millennium BC: Evidence from painted objects excavated at Tol-e Sangi and Hormangan archaeological sites in southern Iran

Abstract

Red, black and white pigments on approximately 70 painted objects including grinding tools, potteries and wall paintings from two Neolithic archaeological sites in southern Iran, namely Tol-e Sangi and Hormangan, dated back to the 7th millennium BC, respectively, were investigated by fibre optics reflectance spectroscopy (FORS), polarised light microscopy (PLM), scanning electron microscopy coupled with energy dispersive X-ray spectrometry (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), micro-Raman spectroscopy (µ-Raman) and micro-X-ray fluorescence (µ-XRF). It is demonstrated that red ochre together with calcium carbonate are used as red and white pigments, respectively, while the black pigments include different manganese oxides and black chromite. We therefore document the first occurrence of chromite used as pigment in decorating archaeological pottery. It is also shown that the red ochre occurred on the objects from Hormangan contains considerable amounts of arsenic in contrast with those found at Tol-e Sangi pointing to different sources used for decorating the painted objects from these archaeological sites.