Micro-Raman, XRD and THM-Py-GC/MS analysis to characterize the materials used in the Eleven-Faced Guanyin of the Du Le Temple of the Liao Dynasty, China

Abstract

This article aims to systematically and comprehensively analyze the mineral pigments, adhesives and painting techniques of the Eleven-Faced Guanyin of the Du Le Temple in Tianjin, Liao Dynasty, China. Digital microscopy, FESEM-EDS, XRD, micro-Raman spectroscopy, FT-IR and THM-Py-GC/MS scientific microdestructive or nondestructive methods were selected for in-depth study. The investigation shows that the mineral pigments principally contained black (carbon), red (minium or cinnabar), orange (minium and litharge (tetragonal PbO)), blue (ultramarine blue and blue sodalite), green (atacamite), cyan (malachite) and gold (mainly referring to Au and Ag powders). Furthermore, adhesives used in the gold areas were heat-bodied tung oil, while adhesives used in other color areas were glue-protein. Additionally, during the study of the painting techniques, “gilding technique” was also found in the gold areas.