Mineralogical and thermal analysis of the Neolithic ceramic from Ghaf Khāneh, a late Sixth millennium BCE site in Northeast Iran

Mineralogical and thermal analysis have examined Neolithic ceramic sherds from Ghaf Khāneh, a site dated ca. 5200–5000 BCE, i.e., the early phase of Cheshmeh Ali culture in northeast Iran. This research includes fifteen sherd fragments recovered from archaeological excavation at this site. The ceramic assemblage of the site is overwhelmed by the Red Ware, comprising almost 95 percent of the whole, while the Gray Ware and Buff Ware constitute minor ceramic groups. This study aims to identify each ceramic group’s mineralogical and chemical characteristics and evaluate the mineralogical behavior (phase decomposition) during the firing process, kiln atmosphere, the firing temperature, and factors that may affect the mineral behavior. Buff and Red Ware display diopside and hematite phases within their fabrics, which indicate the role of these phases in coloring. The studied samples contained muscovite, calcite, and microcline phases; these phases have been considered thermobarometers. According to petrographical studies, XRD analysis, and TG-DTA curves, Red Ware and Buff Ware can be classified into two groups: those fired above 850 °C and those fired below 750 °C, while Gray Ware was fired below 750 °C. Certain phases in the studied samples may provide insight into ancient potters’ knowledge and familiarity with various clayey resources.