Nondestructive characterization of ancient faience beads unearthed from Ya’er cemetery in Xinjiang, Early Iron Age China

Abstract

Abstract Faience is a kind of ancient ceramic product which was widely found in many areas. Chinese faience appeared in the Western Zhou Dynasty (1046-771BCE), about three thousand years later than western Asia. The sudden and late emergence of Chinese faience implies that its production technology may be influenced by the West. However, little information is known about how the faience productions spread from the West to central China. The Xinjiang Uygur Autonomous Region, located in the northwestern part of China, is one of the most important areas of cultural exchanges between the East and the West since ancient times. The study of faience unearthed in Xinjiang is of great significance to explore the early trade and cultural exchanges between central China and the West. In this paper, Synchrotron Radiation Micro-CT (SR-μCT) and Energy dispersive X-ray fluorescence spectroscopy (EDXRF) have been applied to obtain the information of microstructure and chemical composition of faience beads excavated from Ya’er cemetery (1050-300BCE) in Hami Basin, The Xinjiang Uygur Autonomous Region, China. These faience beads are the earliest faience artifacts in China up to our knowledge and this is the first time to analyze the excavated faience in Xinjiang scientifically. Based on the microstructure of faience beads in CT slices, it is found that two glazing methods, direct application and efflorescence, were used in faience production. Additionally, a cylindrical core made of organic material sustained the faience bead during shaping and firing. According to EDXRF analysis, various glaze recipes have been used to produce these faience beads, possibly indicating different provenance. The characteristics of higher Na2O/K2O ratio of faience glaze showed that these faience beads might come from the West. Thus, it is suggested that there was a faience road from Western Asia through Xinjiang to central China about three thousand years ago.