Glassmaking remains from the 12th to 14th centuries CE glass workshop in Boshan, Shandong Province, China

•We conducted chemical and micro-structural analysis on the glass remains and glass crucibles unearthed from a glass workshop dated back to 12 to 14 centuries in China, determining that the glass recipe included feldspar, quartz, nitrate, fluorite, colorants, and probably calcite.•These minerals match those in the glass recipes recorded in the historical literature.•Based on these remains, we find that glass making at that time comprised at least two steps, namely the pre-melting of raw materials into a semi-finished glass, to which more fluxes were then added to make the final glass products or ingots.•The study combines the historical literature and scientific analysis of the archaeological remains to rebuild the ancient glass-making recipe and process with firm evidence, giving more details to Chinese glass handcrafting history. Many glass furnaces producing K2O-CaO-SiO2 glass were excavated in Yanshen Town, Zibo city, Shandong province, dating to the Jin to Ming Dynasties, a large-scale glass-making center recorded in historical sources. According to the typological study of ceramics, the workshop which produced the studied samples dated from the Jin to the Yuan Dynasties (12th to 14th centuries CE), and is one of the earliest archaeological glass workshops found in China. The workshop yielded many semi-finished glass fragments, final products, and glass crucible fragments. We conducted chemical and micro-structural analysis by LA-ICP-AES and SEM-EDS, determining that the glass recipe included feldspar, quartz, nitrate, fluorite, colorants, and probably calcite. These minerals match those in the glass recipes recorded in the historical literature. Glass making comprised at least two steps, namely the pre-melting of raw materials into a semi-finished glass, to which more fluxes were then added to make the final glass products or ingots.