Appendix 2 - Preliminary chemical and mineralogical analyses of diagnostic samples of opaque glazed pottery from Istakhr

Six opaque glazed samples from Istakhr have been analysed:93 four come from the 2012 campaign of the Iranian-Italian Archaeological Mission (samples 13, 14, 17, 30) and two from the campaigns conducted by E. Herzfeld in the 1930s (samples 15, 29; table 2). These archaeometrical analyses mainly focused on the ceramic bodies and glazes. All the fabrics were first analysed by X-ray powder diffraction (XRPD) to identify the principal mineral phases. The ceramic body was mechanically separated from the glaze and the surface layers were removed by using a chisel - in order to avoid possible contamination - and then ground and analysed. This is a rapid analytical technique used to achieve a preliminary screening of the ceramic bodies, as well as a powerful method for studying the dynamics of firing in terms of mineral changes. Later on, the thin sections of the samples were microscopically analysed under a transmitted polarised light microscope, which led to the detection of a specific combination of a clay matrix, inclusions and voids thus enabling the textural, shape and microstructural characteristics of specific petrographic fabrics to be identified. Finally, analyses were performed by scanning electron microscopy (SEM)94 for secondary electrons (SE) and backscattered electrons (BSE), and imaging and energy dispersive spectroscopy (EDS) in order to obtain a chemical qualitative analysis of specific components of the ceramic body and glaze, respectively.