Archaeometric and archaeological study of painted plaster from the Church of St. Philip in Hierapolis of Phrygia (Turkey)

This paper presents the results of archaeometric and archaeological study of the fragments of painted plaster discovered during the recent archaeological investigations inside the Church of the Apostle Philip in Hierapolis of Phrygia, one of the great Hellenistic, Roman and Byzantine cities of southwestern Turkey (Pamukkale, Denizli Province). The analyses were firstly performed, directly on site, at the deposit of the Italian Archaeological Mission in Hierapolis where all the excavated materials were stored, using a protocol including non-invasive techniques based either on imaging (Ultraviolet fluorescence and Visible Induced Luminescence) or single spot analyses (Fiber Optic Reflectance Spectroscopy and portable X-Ray Fluorescence spectrometry). Then, the most representative and interesting samples were sampled for further studies with laboratory techniques such as optical and electron microscopy, Fourier Transform Infrared Spectroscopy, micro-Raman and X-ray diffraction. The following pigments were identified: red ochres and minium for the red, lapislazuli and Egyptian blue for the blue, ochres for the yellow and carbon for the black. Lapislazuli and minium were found in the apse area, and, in particular, minium in the Early/Middle-Byzantine phase. Regarding the plasters, a different number of layers was identified for the Middle-Byzantine fragments that present an inner painted layer.