Estimation of ancient firing technique by the characterization of semi-fused Hellenistic potsherds from Harabebezikan/Turkey

This study discusses the availability of different ancient firing techniques for some semi-fused potsherds which were recovered from an archeological excavation carried out for a Hellenistic workshop at Harabebezikan (Turkey). There are different ancient firing techniques such as open or surface firing (bonfire), pit firing and kiln firing. Each firing technique may create different effects on pottery. It sometimes may be possible to distinguish the firing technique used for a pottery if some evidential characteristics of firing could be defined. The potsherds were characterized with different analytical techniques in order to enlighten firing technique used for the production. Wavelength dispersive X-ray fluorescence (WDXRF) and X-ray diffraction (XRD) analysis were performed for chemical and mineralogical/phase contents, respectively. Scanning electron microscopy (SEM) in combination with energy dispersive X-ray spectrometry (EDX) was further performed for microstructural and microchemical characterization. Quartz (SiO2), calcite (CaCO3), plagioclase [(Na,Ca)AlSi3O8], hematite (α-Fe2O3), pyroxenes [Ca(Mg,Al)(Si,Al)2O6]/[Ca(Mg,Fe)Si2O6], akermanite (Ca2MgSi2O7) and leucite (KAlSi2O6) were identified in the samples. Abundance of new mineral formations in the samples, related firing temperatures, microstructural and microchemical investigations suggested that kiln firing was the most probable technique for the production of the investigated potsherds.