At the earliest stages of the development of what we now call porcelain, the Chinese potters seems to have been using a natural clay that fired reasonable white without any alterations of additions of foremost Kaolin. This is thought to have occured in the Jiangxi province where the city of Jingdezhen is now located.
White firing ceramic wares occured in China, in the Tang dynasty and also as early as the Shang dynasty when this probably found used in the bronze industy.
Later, the body material porcelain got to be made of, from the Yuan dynasty and later, is called a paste, since it is man made and not made through a natural basic geological process.
See also: Porcelain paste.