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Kaolinite is a mineral with the chemical composition Al2Si2O5(OH)4. It is also known as china clay and kaolin (高嶺土 in pinyin: gao1 ling3 tu3), named after Gaoling ("High Hill"), Jingde Town, Jiangxi, China.

It is a soft, earthy, usually white mineral (dioctahedral phyllosilicate clay), produced by the chemical weathering of feldspar. In many parts of the world, it is colored red-orange by iron oxide, giving it a distinct rust hue. Lighter concentrations yield a yellow or light orange colour. Alternating layers are sometimes found, as at Providence Canyon State Park in Georgia, USA.

Used in medicine, bricks, paper and in ceramics and one of the most common minerals, it is mined in France, Britain, Germany, Japan (Amakusa), China, and the southeastern U.S. states of Georgia, Florida, and, to a lesser extent, South Carolina. Due to its extremely fine nature (like silt), it is mixed with water and transported in tanks as a liquid slurry. A major use is to soothe upset stomach, as in the medicine brand Kaopectate similar to the way parrots[1] (and later, humans) in South America originally used it.

The crystallography of kaolinite played a role in Linus Pauling's work on the nature of the chemical bond.

Kaolinite is the primary ingredient in a new pesticide, sold under the trade name Surround, which is used in favor of more toxic materials, particularly in organic farming. It's effectivness consists not in killing pest insects, but rather in putting a physical barrier on the plants or fruits.

See also: List of minerals, porcelain