Chinese imperial Song ware made in Ru kiln in Baofeng County, Henan Province. The Ru kilns were commissioned to produce Celadon ware for the court which replaced the northern, white Ding ware as the favored imperial ware. Unlike Ding - which was fired upside down leaving the rim bare of glaze - Ru ware was fired on spurs so that the glaze covered the entire vessel. The ware is characterised by the fine fire support marks on the bases of the vessels, resembling sesame seeds, its pale lavender glaze with crackle known as "crab's claw markings" and an ash-gray body. There are less than 100 authentic pieces known in the world.