|Earthenware with variegated, surface colour made in Stoke-on-Trent, England, in the 18th century. It was a subdivision of the "clouded" (agate) ware made about 1755-60 at Stoke-on-Trent, especially by the famous potter Thomas Whieldon.|
The brown colour of the tortoiseshell ware is derived from manganese oxide. The different clouded effects were obtained by treating the lead glaze with different oxides; only that with brown mottling is properly called "tortoiseshell," though the term is often used loosely to include multicoloured clouded ware in general.
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