Synthesis and Raman study on needlelike silicates in ancient Chinese Pb-Ba glass in Qin and Han dynasties

Two ancient green Chinese Pb-Ba glass (Qin and Han dynasties) were studied with Raman microspectroscopy, scanning electron microscopy, and energy dispersive X-ray spectrometry. Some needlelike silicates were found in the samples and inferred as BaSiO3, BaSi2O5, and PbSiO3 according to the results of energy dispersive X-ray spectrometry analysis. Then BaSiO3, BaSi2O5, and PbSiO3 were synthetized in laboratory in order to obtain their Raman spectra. Through comparative study, the needlelike silicates in the ancient Pb-Ba glass samples were proved to be PbSiO3, BaSiO3, and Al2O3. According to the ternary phase diagram analysis, a mechanism of local element enrichment was put forward for the barium silicate needlelike silicates (by-products) formation in the ancient Pb-Ba glass. Copyright © 2014 John Wiley & Sons, Ltd.