Organoclays or nanoclays have gained increased attention from industry as well as academia during the past 1 1/2 decades. These clays are prepared from natural clays which invariably have other minerals as impurities. It is of prime significance to remove impurities from organoclays which find applications in polymer nanocomposites, paints, cosmetics, and medicinal formulations. The Indian bentonites were treated with sulfuric acid, hydrochloric acid, hydrogen peroxide, oxalic acid, citric acid, and sodium dithionite to remove impurities invariably present in natural clays. Treatment with both minerals and organic acid could remove both interlayer and structural iron and improve the whiteness with breaking up layered structure. However, sodium dithionite treatment is observed to be more suited to remove iron impurities from bentonite and improve whiteness to 11% without any effect on the structure of the clay. Chemically treated bentonites were used for preparing organoclays in a single step to eliminate the filtration and washing steps. The organoclays were prepared under varied reaction parameters such as temperature, the amount and type of organic modifier, and the concentration of the clay. The optimization of these parameters was done to prepare orgnaoclays with controlled particle size and whiteness.