[Raman microspectroscopic analysis of polychrome wooden artifact from the Astana tomb of the tang dynasty, Xinjiang, China].

The Turpan District is characterized by a typical dry climate, so that many organic relics have been well preserved. A piece of wooden artifact with 9 colors was unearthed from Astana graveyard which is rich in cultural connotations. In the present paper, Raman microscopy was employed for in-situ, nondestructive analysis of pigments that remained on this artifact, and many mineral pigments (gypsum, red lead, carbon black, haematite, atacamite) and vegetable dyes (gamboges and indigo) were identified. It is noteworthy that this is the earliest example that gamboges were used as yellow dye in China at present. The results show that the Gaochang people had mastered skills proficiently, including the preparation, deployment and usage of pigment. The investigation of pigments could provide a basis for the restoration and conservation of relies, and more evidence for pigments trade business and cultural exchanges.