Petuntse (from 白墩子 in

pinyin Hanyu Pinyin (), often shortened to just pinyin, is the official romanization system for Standard Mandarin Chinese in China, and to some extent, in Singapore and Malaysia. It is often used to teach Mandarin, normally written in Chinese for ...

: ), also spelled petunse and ''bai dunzi'', ''baidunzi'', is a historic term for a wide range of

micaceous Micas ( ) are a group of silicate minerals whose outstanding physical characteristic is that individual mica crystals can easily be split into extremely thin elastic plates. This characteristic is described as perfect basal cleavage. Mica is ...

feldspathic Feldspars are a group of rock-forming aluminium tectosilicate minerals, also containing other cations such as sodium, calcium, potassium, or barium. The most common members of the feldspar group are the ''plagioclase'' (sodium-calcium) feldspa ...

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 A ceramic is any of the various hard, brittle, heat-resistant and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay, at a high temperature. Common examples are earthenware, porcelain ...

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

ball clay Ball clays are kaolinitic sedimentary clays that commonly consist of 20–80% kaolinite, 10–25% mica, 6–65% quartz. Localized seams in the same deposit have variations in composition, including the quantity of the major minerals, accessory ...

). It was, and to some extent continues to be, an important raw material for

Chinese porcelain Chinese ceramics show a continuous development since pre-dynastic times and are one of the most significant forms of Chinese art and ceramics globally. The first pottery was made during the Palaeolithic era. Chinese ceramics range from construc ...

, although the terms "porcelain stone", or "pottery stone", are now used. The equivalent term in Chinese is ''cishi''. It is mixed with

kaolin Kaolinite ( ) is a clay mineral, with the chemical composition Al2 Si2 O5( OH)4. It is an important industrial mineral. It is a layered silicate mineral, with one tetrahedral sheet of silica () linked through oxygen atoms to one octahedral ...

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. There are large deposits of high quality stone in

Jiangxi Jiangxi (; ; formerly romanized as Kiangsi or Chianghsi) is a landlocked province in the east of the People's Republic of China. Its major cities include Nanchang and Jiujiang. Spanning from the banks of the Yangtze river in the north int ...

province in south-eastern China, which became a centre for porcelain production, especially in

Jingdezhen ware Jingdezhen porcelain () is Chinese porcelain produced in or near Jingdezhen in Jiangxi province in southern China. Jingdezhen may have produced pottery as early as the sixth century CE, though it is named after the reign name of Emperor Zhenzon ...

.Vainker, p. 124. While sharing some similarities to the material known as

China stone China stone is a medium grained, feldspar-rich partially kaolinised granite characterized by the absence of iron-bearing minerals.mineralogy Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical) properties of minerals and mineralized artifacts. Specific studies within mineralogy include the proces ...

. However both are derived from the alteration of

igneous rock Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main The three types of rocks, rock types, the others being Sedimentary rock, sedimentary and metamorphic rock, metamorphic. Igneous rock ...

Notes

References

*Macintosh, D., ''Chinese Blue and White Porcelain'', 3rd ed., 1994, Antique Collectors' Club, *Rose Kerr, Joseph Needham, Nigel Wood, ''Science and Civilisation in China: Volume 5, Chemistry and Chemical Technology'', Part 12, ''Ceramic Technology'', 2004, Cambridge University Press,
google books
* Rawson, Jessica (ed). ''The British Museum Book of Chinese Art'', 2007 (2nd edn), British Museum Press, *Vainker, S.J., ''Chinese Pottery and Porcelain'', 1991, British Museum Press, Chinese porcelain Ceramic materials {{geology-stub