What kind of ceramics is the ash burned with white tires as the base tires?

Longquan celadon in Southern Song Dynasty. The tire bottom of Longquan celadon in the Southern Song Dynasty is characterized by simplicity, thick bottom, wide and short round foot, exposed tire with large bottom, mainly carved decoration, and white, dark and gray tire color. Ceramic is the general name of pottery and porcelain, and it is also a kind of handicraft. As early as the Neolithic Age, there were rough and simple painted pottery and black pottery. Pottery and porcelain have different textures and characteristics.