Azure glaze in particular to Henan in the Song dynasty ru-Royal a celadon glaze firing. Agate, composed primarily of silica, silica, the main ingredient of Ru kiln glaze, no different from glazes with General quartz sand, agate often contain colored elements such as iron, to increase the special luster of ru ware has a role. Based on physical observations, ru-splashed pale blue glaze is mainly characterized by glaze layer uniform, glazed and moist, green jade-like stone thick, like a pile of fat. After the reduction flame burning, blue glaze, such as clear skies. Crab claw lines, Roe line unveiled by glazing, glazing table has a scaly the fish pieces.