Montmorillonite is a type of clay that is widely used in a variety of industries, including agriculture, construction, and medicine. There are several synonyms for this versatile mineral, including bentonite and smectite. Other related terms include clay minerals, colloidal clays, and swelling clays. Bentonite is perhaps the most commonly used synonym for montmorillonite, as it refers to a specific type of clay formed from the weathering of volcanic ash. Smectite, on the other hand, refers to a group of clay minerals that includes montmorillonite, but also other types such as saponite and hectorite. Regardless of the specific term used, montmorillonite and its synonyms play an important role in many industrial processes, from drilling fluids to wastewater treatment. Their unique properties, such as high surface area and water-holding capacity, make them highly versatile and valuable materials.