Petuntse (from 白墩子 in pinyin: bai2 dun1 zi0), also spelled petunse, is a historic term for a wide range of micaceous or feldspathic rocks. However, all will have been subject to geological decomposition processes that result in a material which, after processing, is suitable as an ingredient in some ceramic formulations. Petuntse was and continues to be an important ingredient of Chinese porcelain. The term pottery stone is now used. While sharing some similarities to the material known as China stone, found uniquely in southwestern England, they differ in mineralogy. However both are derived from decomposition of igneous rocks.