Petuntse

Petuntse (from Chinese: 白墩子; pinyin: báidūnzì), also spelled petunse and bai dunzi, baidunzi, is a historic term for a wide range of micaceous or feldspathic rocks.

The name means "little white bricks", referring to the form in which it was transported to the potteries (compare ball clay).

[12][13] According to one source, it is mixed with kaolin in proportions varying according to the grade of porcelain to be produced; equal quantities for the best and two thirds petuntse to one third kaolin for everyday ware.

[14] There were large deposits of high-quality stone in Jiangxi province in south-eastern China, which became a centre for porcelain production, especially in Jingdezhen ware.

[24][25][26] Relatively similar material to China stone has been mined, and exported to England for ceramics use, in the Isle of Man and Jersey.

19th century illustration of the extraction of petuntse and kaolin in China
A lump of Japanese pottery stone