Multi-Method Analysis of Painting Materials in Murals of the North Mosque (Linqing, China)

The murals of Ming Dynasty North Mosque in Linqing, Shandong Province, Eastern China, are of significant cultural and historical importance. Their final restoration date remains uncertain, making a comprehensive investigation critical before initiating preservation and renovation work. This research project examined the painting materials of the murals using various analytical techniques, including polarized light microscopy (PLM), scanning electron microscopy (SEM), X-ray energy spectrometer (EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), microscopic Raman spectroscopy (M-Raman), X-ray photoelectron spectroscopy (XPS), and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) analysis. Results indicated that the pigments employed included ultramarine, emerald green, cinnabar, kaolinite, gypsum, and carbon black, while the gum binder used was protein-based adhesive materials. As synthetic ultramarine and emerald green were not introduced to China until the late Qing Dynasty, this suggests that these murals were restored no earlier than this period. The study also revealed that the mural materials used in the North Mosque mural were similar to those found in other architectural murals in China. Thus, the knowledge gained from the conservation and restoration efforts of similar architectural murals can be leveraged to enhance the conservation and restoration efforts of the North Mosque murals.