Clay is a type of fine-grained, naturally occurring sedimentary rock that is composed mainly of hydrous aluminum silicates. It is formed from the weathering and erosion of rocks, and is often found in areas with high humidity or near sources of water. Clay is widely used in a variety of industries, including ceramics, construction, papermaking, and drilling.Clay has a number of properties that make it useful for these and other applications. It is highly plastic when wet, meaning it can be molded and shaped easily. It is also highly absorbent, and can be used to filter or purify liquids. Clay is also resistant to heat and can withstand high temperatures without breaking down, making it useful in the production of ceramics and other materials.