Shahr-i Sokhta in Sistan is one of the most significant and pivotal archaeological sites in southeastern Iran, with initial settlement dating back to the Bronze Age (3200 BCE). The site spans an area of approximately 151 hectares, of which 120 hectares contain material and cultural remains. It consists of three major parts: the central area, the industrial zone, and the cemetery. Excavation results indicate four cultural-occupational phases (I–IV), which are further subdivided into eleven sub-phases. Pottery, being the most abundant cultural-historical artifact found across many archaeological sites in southeastern Iran, including Shahr-i Sokhta, holds considerable importance in archaeological studies. It is the only category of ancient object that has survived through millennia with minimal alteration. Archaeologists believe that most of the pottery discovered at Shahr-i Sokhta was produced locally, either within the site or in satellite workshop areas. To evaluate this hypothesis, the present study employed laboratory methods, including petrographic thin section analysis using a polarizing microscope (OPM) and X-ray Powder Diffraction (XRPD), on three buff pottery samples recovered from grave no. 8525 NFB at the site. The analytical results, when compared with the local geology, indicate that the buff pottery from this site is of local origin. Furthermore, based on structural analysis and the presence of calcite grains, a firing temperature of approximately 800°C is suggested for some samples, while others likely underwent firing at around 900°C.
