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Terracotta, terra cotta or terra-cotta (Italian: "baked earth",〔(Merriam-Webster.com )〕 from the Latin ''terra cocta''),〔("Terracotta" ), p. 341, Delahunty, Andrew, ''From Bonbon to Cha-cha: Oxford Dictionary of Foreign Words and Phrases'', 2008, OUP Oxford, ISBN 0199543690, 9780199543694〕 a type of earthenware, is a clay-based unglazed or glazed ceramic,〔OED, "Terracotta"; ("Terracotta" ), MFA Boston, "Cameo" database〕 where the fired body is porous. Terracotta is the term normally used for sculpture made in earthenware, and also for various utilitarian uses including vessels (notably flower pots), water and waste water pipes, bricks, and surface embellishment in building construction,〔'Industrial Ceramics.' F.Singer, S.S.Singer. Chapman & Hall. 1971. Quote: "The lighter pieces that are glazed may also be termed 'terracotta.'〕 The term is also used to refer to the natural, brownish orange color, of most terracotta, which varies considerably. This article covers the senses of terracotta as a medium in sculpture, as in the Terracotta Army and Greek terracotta figurines, and architectural decoration, and it is worth repeating that Asian and European sculpture in porcelain is not covered. Glazed architectural terracotta and its unglazed version were used in Asia for some centuries before becoming popular in the West in the 19th century. In archaeology and art history, "terracotta" is often used to describe objects such as figurines not made on a potter's wheel. Vessels and other objects that are or might be made on a wheel from the same material are called earthenware pottery; the choice of term depends on the type of object rather than the material or firing technique.〔Peek, Philip M., and Yankah, ''African Folklore: An Encyclopedia'', 2004, Routledge, ISBN 1135948720, 9781135948726, (google books )〕 Unglazed pieces, and those made for building construction and industry, are also more likely to be referred to as terracotta, whereas tableware and other vessels are called earthenware (though sometimes terracotta if unglazed), or by a more precise term such as faience. ==Production and properties== An appropriate refined clay is formed to the desired shape. After drying it is placed in a kiln or atop combustible material in a pit, and then fired. The typical firing temperature is around , though it may be as low as in historic and archaeological examples.〔Grove, 1〕 The iron content, reacting with oxygen during firing, gives the fired body a reddish color, though the overall color varies widely across shades of yellow, orange, buff, red, "terracotta", pink, grey or brown.〔Grove, 1〕 In some contexts, such as Roman figurines, white-colored terracotta is known as pipeclay, as such clays were later preferred for tobacco pipes, normally made of clay until the 19th century. Fired terracotta is not watertight, but surface-burnishing the body before firing can decrease its porousness and a layer of glaze can make it watertight. It is suitable for use below ground to carry pressurized water (an archaic use), for garden pots or building decoration in many environments, and for oil containers, oil lamps, or ovens. Most other uses, such as for tableware, sanitary piping, or building decoration in freezing environments, require the material to be glazed. Terracotta, if uncracked, will ring if lightly struck. Some types of terracotta are created using recycled terracotta ("grog"). Painted ("polychrome") terracotta is typically first covered with a thin coat of gesso, then painted. It has been very widely used but the paint is only suitable for indoor positions and is much less durable than fired colors in or under a ceramic glaze. Terracotta sculpture was very rarely left in its "raw" fired state in the West until the 18th century.〔Grove, 2, i, a〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「terracotta」の詳細全文を読む スポンサード リンク
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