Bentonite is an absorbent swelling clay mineral with two major types: sodium bentonite and calcium bentonite. The bentonite found in Wyoming is sodium bentonite, which is comprised of hydrous silicate alumina – known as montmorillonite clay. It has unique characteristics that make it high-swelling and extra absorbent. It can swell up to 16 times its original size and absorb up to 7 times its own weight in water. Wyoming’s bentonite was created by high concentrations of sodium in the seawater where volcanic ash fell during the Upper and Lower Cretaceous periods, 145 million to 66 million years ago.

Wyoming bentonite is called the clay of 1000 uses because of its widespread applications. Many of these applications fall within the construction, manufacturing and energy industries. The most common uses include as a clumping agent in cat litter, drilling mud, a binder in foundry molds, and iron ore pelletizing. But it is also found in crayons and even lipstick.