Investigations by Raman microscopy, ESEM and FTIR-ATR of wall paintings from Qasr el-Ghuieta temple, Kharga Oasis, Egypt

Abstract

In the present work, a multi-analytical approach was used to analyze samples collected from the wall paintings of Qasr el-Ghuieta temple, Kharga Oasis, Egypt. The temple is dating back to the 27th dynasty (525-404 BC) and was completed during the Ptolemaic period. The samples were analyzed by optical microscopy (OM), environmental scanning electron microscopy (ESEM) coupled with an energy dispersive X-ray analysis system (EDX), Raman microscopy and Fourier transform infrared-attenuated total reflectance spectroscopy (FTIR-ATR). The chromatic palette used in the temple was identified as Egyptian blue (cuprorivaite), red ochre (haematite), yellow ochre (goethite) and carbon black (from a vegetable origin). The green pigment was identified as green earth, however, a green tonality was also obtained through a mixture of Egyptian blue and yellow ochre, and in some samples, carbon black was also found. Several amounts of anatase and carbon black were found in the red and yellow ochre samples, respectively. The analysis showed that the preparation layer is almost made of pure gypsum, while the plaster layer based mainly on gypsum with variable amounts of quartz, calcite and clay minerals. The results showed that the painting materials and techniques used in the temple are almost the same of those used in the Egyptian temples with respect to the stratigraphy of paint layers, chromatic palette and the painting technique employed.