Bentonite is the name given to a variety of clays that occur naturally in the environment. All forms of bentonite contain the element silicon along with at least one additional mineral. Each type of bentonite clay has its own benefits and specific uses. A form of bentonite that contains aluminum silicates is a common ingredient in skin care products. Other types of bentonite may also be found in a small number of beauty products as well.
In nature, bentonite forms due to the breakdown of volcanic ash. After a volcanic eruption, debris is spread for miles in the surrounding areas, where it becomes a part of the soil. With time, chemicals already present in the ground and the actions of wind and rain break up the ash, and as a result, large deposits of bentonite clays form. While these clays can be harvested and used in skin care products, some companies manufacture bentonite from its raw ingredients.
Bentonite was formally identified in 1898 by Wilbur C. Knight who named the substance after a deposit of shale in Wyoming where he obtained the clay for studying. Long before it was given an official name, bentonite was used as a medicinal treatment for wounds as well as in natural skin care remedies. The ancient Mesopotamians are the first civilization known to use bentonite and other medicinal clays.
When used as an active ingredient in skin care products, bentonite is typically included in formulas because of its absorbency. The clay consists of very tiny flakes with small amounts of space between them. These small spaces readily accept fluids, and once the clay has pulled these liquids into the spaces, it retains them. This property of bentonite makes it very useful for absorbing oil from the complexion.
Often, masks that contain bentonite are used all over the face to help normalize oily skin. It can also be used only in the t-zone to alleviate oily shine that is typical in combination skin types. For acne sufferers and those with enlarged pores, bentonite helps to eliminate the oil that clogs the pores and can help reduce the frequency of blemishes and allow the pores to return to their normal size.
One problem with the use of bentonite clay masks is that the ingredient does not discriminate between types of fluids when it is applied to the skin. Since all types of fluids can fill the spaces between the flakes that make up the ingredient, bentonite can absorb too much of the skin's natural oil. If this occurs, the skin tissue becomes dehydrated and may feel itchy or look flaky. The drying effects of bentonite can be mitigated by applying a moisturizer designed for oily skin after washing away a mask and by limiting the frequency with which the clay masks are used.
Some skin care products use the flakes of bentonite as an exfoliating material. These formulas create friction on the skin and remove the outermost, dead skin cells from the complexion. Products that feature bentonite as an exfoliator include rinse-away body scrubs and exfoliating lotions and creams. When used as an exfoliant, bentonite can help resurface the complexion to make fine lines and wrinkles less noticeable and reduce the appearance of skin discoloration. Regular exfoliation also helps prevent the pores from becoming clogged, which is beneficial for treating acne, ingrown hairs and enlarged pores.
In addition to its use as an active agent for absorbing oil, bentonite also frequently serves as an additive in skin care products. Its inclusion in liquid cosmetics and skin care products helps prevent formulas from forming clumps. Foundations that contain trace amounts of bentonite are less likely to appear cakey when applied to the skin. Bentonite can also be added to skin care products to increase their thickness or viscosity and to prevent them from separating. The inclusion of bentonite in formulas also reduces the transparency of creams, gels and lotions, making products more visually appealing.
Apart from skin dryness, bentonite is not known to cause side effects and is not a common allergen. Because of its natural origins, bentonite is a common ingredient in natural skin care lines, including organic and vegan products.