WClay is a type of fine-grained natural soil material that contains hydrous aluminium phyllosilicates that develops plasticity when wet. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure. Clays are plastic due to particle size and geometry as well as water content, and become hard, brittle and non–plastic upon drying or firing. Depending on the soil's content in which it is found, clay can appear in various colours from white to dull grey or brown to deep orange-red.
WA clay court is a tennis court that has a playing surface made of crushed stone, brick, shale, or other unbound mineral aggregate. The French Open uses clay courts, making it unique among the Grand Slam tournaments. Clay courts are more common in Continental Europe and Latin America than in North America, Asia-Pacific or Britain. Two main types exist: red clay, the more common variety, and green clay, also known as "rubico", which is a harder surface. Although less expensive to construct than other types of tennis courts, the maintenance costs of clay are high as the surface must be rolled to preserve flatness.
WA clay pit is a quarry or mine for the extraction of clay, which is generally used for manufacturing pottery, bricks or Portland cement. Quarries where clay is mined to make bricks are sometimes called brick pits.
WCob, cobb or clom is a natural building material made from subsoil, water, fibrous organic material, and sometimes lime. The contents of subsoil naturally vary, and if it does not contain the right mixture it can be modified with sand or clay. Cob is fireproof, resistant to seismic activity, and uses low-cost materials, although it is very labour intensive. It can be used to create artistic and sculptural forms, and its use has been revived in recent years by the natural building and sustainability movements.
WEarthenware is glazed or unglazed nonvitreous pottery that has normally been fired below 1,200 °C (2,190 °F). Basic earthenware, often called terracotta, absorbs liquids such as water. However, earthenware can be made impervious to liquids by coating it with a ceramic glaze, which the great majority of modern domestic earthenware has. The main other important types of pottery are porcelain, bone china, and stoneware, all fired at high enough temperatures to vitrify.
WFire clay is a range of refractory clays used in the manufacture of ceramics, especially fire brick. The United States Environmental Protection Agency defines fire clay very generally as a "mineral aggregate composed of hydrous silicates of aluminium (Al2O3·2SiO2·2H2O) with or without free silica."
WMetal clay is a crafting medium consisting of very small particles of metal such as silver, gold, bronze, or copper mixed with an organic binder and water for use in making jewelry, beads and small sculptures. Originating in Japan in 1990, metal clay can be shaped just like any soft clay, by hand or using molds. After drying, the clay can be fired in a variety of ways such as in a kiln, with a handheld gas torch, or on a gas stove, depending on the type of clay and the metal in it. The binder burns away, leaving the pure sintered metal. Shrinkage of between 8% and 30% occurs. Alloys such as bronze, sterling silver, and steel also are available.
WA moorish oven is a traditional clay wood-fired oven.
WPaper clay is any clay body to which processed cellulose fiber has been added.