
Clay
This relief is thought to have been originally from Mogao Caves 248 to 250. The top of the niche defines the nimbus about the head of the figure. The Buddha sits cross-legged with hands in dhyana (meditation) mudra. The broad folds of the monastic robe are painted in complementary colors to bring out the contrast.
For more details, go to the Encyclopedia of Buddhist Arts: Caves Mo-S, page 1246.