Fig. 5From: Blue pigments in Cave 256, Mogao Grottoes: a systematic analysis of murals and statues in Five dynasties, Song Dynasty and Qing DynastyInfrared spectrum of blue pigment used in Cave 256. a Infrared spectrum of blue pigment particles. b Infrared spectrum of green pigment particles. c Infrared spectrum of blue pigment used in the Qing DynastyBack to article page