Ash glaze
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Ash Glaze are types of high temperature glazes for stoneware pottery that include the ashes of trees, shrubs, plants or grasses within the glaze recipe.
Plant ashes are a complex mixture that reflects the nutritional requirements and therefore composition of the living plant. High in calcium and also incorporating other alkaline material, ash behaves as a flux encouraging the glass forming oxide silica to melt at a temperature within the scope of a pottery kiln. Ash glazes often have a characteristic mottled or streaky texture depending on the amount of ash incorporated.
Ash glaze is the earliest form of high temperature glaze[citation needed]. Ash settling upon the pots in a woodfired kiln combined with the silica within the clay to form crude glazes on Chinese pottery 2,000 B.C. The effect can be seen clearly on early Han pieces. The Chinese potters then began to combine ash with clay to create a "recipe" and this mixture was applied to the pot before placing in the kiln to create the first true glaze that wasn't accidental.[citation needed] [dubious — see talk page]
