Celadon (Qingci / Green-Blue Porcelain) / 青磁
Celadon is a type of high-fired stoneware or porcelain that features a grayish body containing iron, coated with a glaze that includes small amounts of ferric oxide (iron oxide), and is fired in a reduction atmosphere. This process produces a green or bluish hue in the glaze. The earliest proto-celadon, using ash glazes, began in China during the Shang dynasty. True celadon ware was first fully developed in northern Zhejiang Province around the Eastern Han period. The technique and style were perfected during the Song dynasty, and celadons from kilns such as Ru (Ruyao), Guan (Guanyao), and Longquan (Longquanyao) were highly esteemed—not only in China but throughout East Asia—as the finest and most prestigious of all ceramics.