Bentonite can be found in three different forms. Sodium bentonite expands when it gets wet and is often used with drilling mud in oil and gas wells. It is also used in boreholes for environmental and geotechnical investigations. The swelling properties of sodium bentonite make it useful as a sealant. Calcium bentonite absorbs ions in solutions along with fats and oils. Potassium bentonite is formed from volcanic ash.
Bentonite has a molecular weight of 422.286 g/mol and a heavy atom count of 21. It also has a hydrogen bond donor count of one and a hydrogen bond acceptor count of 13. The complexity of the compound is 21. Bentonite also has both a monoisotopic and exact mass of 421.8 g/mol.