Mud, gel or drilling clay: We have all used one of these terms to describe bentonite, the most common additive used to make up our drilling fluids. Bentonite is an absorbent aluminum phyllosilicate, typically a montmorillonite clay mined primarily in Wyoming. Most of the bentonite used for drilling fluids is the sodium montmorillonite variety because of its ability to attract and bind to water molecules. The chemical, physical and molecular properties of the bentonite, and how it provides viscosity and gel strength in a water-based drilling fluid, have been discussed in this and other water well publications many times. But did you know that bentonite has many other uses? Let’s look at how this clay is utilized outside of the drilling industry.

Cosmetics: Bentonite clay is utilized in the cosmetics industry in a variety of ways, including an absorbent, bulking agent, suspending agent and as an emulsion stabilizer. If you see the ingredient “Tixoton” on the packaging, you know that bentonite is in the mix. The clay is also used as a thickening agent in lipstick, shampoo and calamine lotion.

Beer making: A clay slurry is added to beer to serve as a “fining” agent. In other words, adding bentonite to beer will remove the very small particles of yeast, tannin and other protein-based solids from the liquid. These small particles make the drink look hazy and most of the drinking public likes bright, clear beer. The use seems straightforward based on several Internet articles. Add the powdered clay to water, shake or use a blender to sheer the bentonite (sound familiar?), let the solution hydrate for several hours and then add to the beer. The negatively charged bentonite attracts the positively charged particles that make the liquid cloudy. The relatively heavy gel sinks to the bottom of the container, stripping the offending material from the beer. Just so the oenophiles in the bunch don’t feel left out, wine is also clarified in the same manner.

bentonite serves a lot of industries beyond drilling.

From beer to bricks, from kitty litter to asphalt, bentonite serves a lot of industries beyond drilling. Source: iStock photos

Thickening agent: Bentonite clay is used as a thickening agent in many everyday products, including water-based paint and coatings, adhesives, polishes and latex/rubber products.

Binder: Bentonite is added to bind the graphite material for “lead” pencils. Flux agents for welding rods are bonded to the rods using bentonite clay. Bentonite is used to bind animal feed and reduces the speed at which food moves through the animal’s digestive system.

In addition to the above, bentonite clay is used in the following products and industries:

• Iron ore

• Asphalt

• Detergents

• Printing

• Paper manufacturing

• Bricks

• Ceramics

• Pond sealing

• Medical – potential blood clotting compound

• Absorbent – “oil dry” and kitty litter

As I researched the uses of bentonite outside of the drilling industry, most of what I found made sense. I could see how the properties of this naturally occurring clay would be useful in a variety of industries. However, I was very surprised to see bentonite used as an internal health supplement.

The Internet is awash in articles detailing the detoxifying benefits of bentonite. Apparently, the negatively charged clay particles remove toxins from our body and provide for “improved intestinal regularity; relief from chronic constipation, diarrhea, indigestion, and ulcers; a surge in physical energy; clearer complexion; brighter, whiter eyes; enhanced alertness; emotional uplift; improved tissue and gum repair; and increased resistance to infections,” according to the website All you need to do is mix some bentonite with water and drink up. If drinking clay does not sound like fun, there are pre-mixed liquid and capsule versions available. Wow, you can’t make this stuff up. Who would have known that the clay we use to drill holes could be used to make us healthier? Just go to the Internet and type “bentonite detox” into any of the search engines and you will be amazed at the number of sites that champion the benefits of drinking clay.

My first interaction with bentonite was over 30 years ago when I was fresh out of college. We were drilling a test hole near Stephenville, Texas. I marveled at how a relatively small amount of clay turned fresh water into a high viscosity/high gel strength drilling fluid. Most of us in the drilling industry knew that this clay had many uses. However, it was a surprise to me that bentonite could be used internally. Please note, however, I am not encouraging/endorsing anyone going out to the shop, taking bentonite from a bag of drilling fluid and mixing a bentonite cocktail. I am sure (and hope) that the material sold for “internal cleansing” is different than what’s in a bag of gel. Like I said earlier, “who knew?”