“…First, Choo has published a single analysis of an 11th-century Korean white porcelain that has a composition typical of a 'single rock' porcelain, such as Jingdezhen yingqing ware (Choo, 1995).There is also an interesting analysis of a rock collected from a 12th-century Korean celadon kiln site, Sadang-ri. This rock consisted of compacted volcanic ash, known as tuff, as did many Chinese porcelain stones of the Jingdezhen type Wood, 1986;nikulina and Taraeva, 1959).…”