Normal phenomenon. Because Tissot starfish ceramic ring is divided into frosted surface and mirror surface, which is a normal phenomenon. Ceramics is the floorboard of pottery and porcelain, and it is also a kind of arts and crafts in China. As early as the Neolithic Age, there were rough and simple painted pottery and black pottery in China. Pottery and porcelain have different textures and characteristics. Pottery, made of clay with high viscosity and strong plasticity, is opaque, with fine pores, weak water absorption and turbid tapping sound.