Bentonite as is a particular kind of clay derived from volcanic ash and consists mainly of montmorillonite with minor amount of illite, kaolinite, cristobalite and other minerals. Bentonite has strong colloidal properties and, when in contact with water, increases its volume several fold by swelling, forming a tixotropic, gelatinous substance. Main uses of Bentonite take advantage of these colloidal properties. The main characteristics of Bentonite is its decolorizing power, that is the property of the earth to absorb selectively certain pigments rather than others according to the characteristics of the product to be decolourized(acidity, oxidation degree, origin and biological state etc.)