Clay is a general term for fine-grained natural earth material composed primarily of aluminum silicates, which, when heated, can undergo chemical changes leading to materials useful in construction and technology. Geologically, clays are formed through the weathering of parent rock material, containing various mineral compounds that determine their specific chemical and physical properties. These materials are utilized industrially because they are highly plastic when moist, allowing them to be molded into various shapes, and they exhibit low permeability. When fired at high temperatures, clay minerals transform into ceramics, creating durable, heat-resistant substances used in applications ranging from structural building elements to complex filtration systems.