Characterization of microcrystals in some ancient glass beads from china by means of confocal Raman microspectroscopy

A total of ten ancient colored glass beads were analyzed by confocal Raman microspectroscopy for the non‐destructive identification of microcrystals within them. These beads were excavated from different regions of China, including Xinjiang, Henan, Hubei and Guangxi Provinces, and were dated mainly from the 10^th century BC to the 9^th century AD. For the first time, either tin or antimony‐based opacifiers/colorants including calcium antimonate (CaSb₂O₆, Ca₂Sb₂O₇), bindheimite (Pb₂Sb₂O₇), lead tin yellow type II (PbSn_1‐xSi_xO₃) and cassiterite (SnO₂) were identified in nine samples. In addition, other crystalline phases such as cuprite (Cu₂O), α‐wollastonite (CaSiO₃), diopside (CaMgSi₂O₆), feldspar (KAlSi₃O₈), calcite (CaCO₃) and quartz (SiO₂) were also detected. Another interesting phenomenon first observed in this study was the coexistence of Sn‐ and Sb‐based opacifiers/colorants in one mosaic bead from Guangxi. The possibility to use Sb‐ and Sn‐based opacifiers/colorants for dating and provenance study of ancient glass found in China is discussed briefly. Copyright © 2013 John Wiley & Sons, Ltd.