Beyond a Decoration; Mineralogical and Micro-structural Study of the Early Bronze Age “Life Cycle Jar” from Keshik Cemetery, Sistan and Balouchistan, Iran

Abstract

The present study focuses on a unique pottery vessel, the so-called “Life Cycle Jar”, and nine other potsherds which were discovered in the Keshik cemetery, Baluchistan, south-east Iran. Samples were investigated through classical analytical methods such as thin-section petrography, X-ray powder diffraction (XRPD), and scanning electron microscopy coupled with energy dispersive X-ray fluorescence (SEM-EDX) to determine the production techniques, fabric characterisation, as well as the pigments applied to decorate the surface of the Life Cycle Jar. Mineralogical and chemical investigations revealed that the pottery pieces were similar in raw materials, and produced locally. Samples show a wheel-thrown signature based on the definite orientation of pores and structural character in their thin sections. The potter pieces were fired under oxidation processes demonstrated by the red and green colour of the matrix. The investigated pottery samples were defined as high-fired sherds (ca. 800–950°C), due to the presence of inclusions in the form of reacted calcite in rhombohedra crystal structure, and hematite within the matrix of the pottery. The microstructural characteristics of the pottery pieces showed that the manufacturing temperature was no higher than 950 °C, by presintering texture. The investigations on the painted decoration on the Life Cycle Jar suggested that iron oxide and manganese oxide was used as the colourant agent in the decoration.