Clay minerals are typically formed by the gradual chemical weathering of rocks, usually silicate-bearing, by low concentrations of carbonic acid and other diluted solvents. Since ancient times, clay minerals have been investigated because of their importance in agriculture, ceramics, building and other uses.

Clays are hydrous alumino-silicates broadly defined as those minerals that make up the colloid fraction of soils, sediments, rocks, and water and may be composed of mixtures of fine grained clay minerals and clay-sized crystals of other minerals such as quartz, carbonate, and metal oxides. Clays play an important role in the environment by acting as a natural scavenger of pollutants by taking up cations and anions either through ion exchange or adsorption or both. Thus, clays invariably contain exchangeable cations and anions held to the surface.

Clays are act as excellent adsorbant materials due to Large specific surface area, chemical and mechanical stability, layered structure, and high cation exchange capacity (CEC).Clays and modified clays have been found particularly useful for adsorption of heavy metals.

Different minerals clays have been used as fillers for preparing hydrogel composites, including Kaolinite, Bentonite, Montmorillonite. Clay is one of the oldest building materials on Earth, among the naturally-occurring geologic materials such as stone and organic materials like wood. Clay is used to create adobe, cob, cordwood, and rammed earth structures and building elements such as wattle and daub, clay plaster, clay renderd, clay paints and ceramic building materials.

Due to their specific properties, e.g., high capillarity, unique rheological properties, hardening, plasticity, thixotropy, high degree of swelling, clays are widely used in various industries. Because of their excellent colloidal properties clays are often used as drilling fluids for oil and gas wells as well as other boreholes to lubricate and cool the cutting tools, to remove cuttings, and help prevent blowouts.One of the important properties of clays is adsorption and ability to interact with the metal ions from the surrounding environment.