Fig. 5: Layered structure of sample C55-1 and part of the analysis results.
From: Investigation on gilding materials and techniques of murals in Cave 55 at Mogao Grottoes
a OM image of C55-1: optical microscope image showcasing the distinct layers within sample C55-1. Yellow arrows and numbers (1-6) indicate different layers or features for identification. b BSE image of C55-1: back-scattered electron microscope image providing a different perspective on the microstructure of the layers in sample C55-1. c Raman spectroscopy of red layer (L2) and green layer (L5): Raman spectra obtained from the red layer (L2) and green layer (L5) of the sample. The spectra reveal characteristic peaks that can be used to identify the chemical composition and molecular structure of these layers. The peaks marked in red are the characteristic Raman peaks of the substance. d XRD pattern of raised-line layer (L3): X-ray diffraction pattern of the raised-line layer (L3). The peaks in the pattern correspond to different crystalline phases, with the legend indicating the possible mineral phases (Quartz, Albite, Microcline, Dolomite, Muscovite-3T, Gypsum) present in this layer.
