China stone (occasionallyCornish stone orCornwall stone) is a medium grained,feldspar-rich partiallykaolinisedgranite characterised by the absence ofiron-bearing minerals.[1]
Its mineral content includesquartz, feldspar andmica; accessory minerals includekaolinite andfluorspar. It is found in one area nearSt Austell,Cornwall in theUnited Kingdom. It was the last UK sourced feldspathic material to be commercially extracted.[2]
A number of varieties, named on the basis of their hardness and physical appearance, were produced.[3] Maximum production was achieved in the early 1950s, with around 70,000 tonnes per annum. The largest producer, English China Clays, ceased production in 1973, when Goonvean Ltd became the sole producer. Due to increasing competition from imported alternatives and a contracting domestic market, sales fell from 8,000 tonnes per year to 2,800 tonnes in 2001.[4][5] The last quarry closed in 2006.[6]
Relatively similar material has been mined, and exported to England for ceramics use, in theIsle of Man andJersey.[7][8][9][10][11][12]
China stone is sometimes confused with the Chinese material traditionally known aspetuntse as well as other Asian pottery stones. However, although somewhat similar they differ inmineralogy.
