Bentonite clay – nature’s beautiful gift

Bentonite clay, as it is commonly known, belongs to the family of smectite clays. To some people bentonite is known as montmorillonite, hectorite or saponite, and to others in the personal care and pharma industries as magnesium aluminium silicate. But what do all these variants have in common? And how do we know which option is best for a face mask, cream or an oral suspension?

To better understand smectite clays, it’s best to start at the beginning. Most smectite clay deposits were formed some 120 million years ago during the Cretaceous period of the Mesozoic era, when winds blew volcanic ashes into the shallow inland seas. The mixture of volcanic ash and decomposing flora and fauna in the inland sea water all contributed to the formation of a mineral we now recognise as bentonite clay.

While each deposit of smectite clay worldwide has a similar origin, each has a unique mineral composition. The names given to each type of smectite clay have simple sources – most names come from the place where the clay in question was first identified and its characteristics catalogued. When it comes to bentonite, the name hails from Fort Benton in the State of Wyoming (USA); montmorillonite originates from Montmorillon in France; hectorite was named after the city Hector near San Bernardino in California (USA); and saponite was first described in 1840 by Lars Fredrik Svanberg, a Swedish chemist and mineralogist.

Although all types of smectite clay have some level of magnesium silicate and aluminium silicate in their deposits, the amount is not equal. For example, montmorillonite is classified as aluminium silicate-based, and saponite is classified as magnesium silicate-based. Because in their respective crystal lattice structures, one metal oxide is more dominant than the other. When you blend them together, you get magnesium aluminium silicate, which is where Vanderbilt Minerals, LLCs’ Veegum product originates.

Unique mineralogical properties

Bentonite clay has been used for centuries for its healing and therapeutic purposes, but mostly as a natural cleanser and skin softener. The cleansing property is most likely due to the large surface area of an otherwise very small platelet size, which has a strong negative charge on both sides of the platelet faces. As a result, it is physically able to attract and bind dirt particles, skin oil and other impurities. The softening effect might be directly associated with the various minerals and organic matter present in the soil when smectite clays were formed.

Although all smectite clays have common characteristics, their function and performance in water-based formulations depend on the unique mineralogical properties of the ores used to produce them, as well as the method used to refine them, so that they can provide useful rheological properties.

The 3D physical colloidal structure, formed by the clays when hydrated in water, is possible due to the attraction of the negatively charged platelet faces of the clay to slightly positive charges on platelet edges. This forms a ‘house of cards’ that keeps the emulsion stable (o/w and w/o) and solids suspended uniformly.

The INCI name does not guarantee that two versions of ingredients called magnesium aluminium silicate or bentonite clay from different suppliers are the same in their properties and performance. One needs to carefully select the supplier and become familiar with their type of minerals to feel comfortable using the ingredient.

Highly beneficial, multifunctional ingredients

Today, consumers are looking for fewer chemicals and more natural ingredients in their everyday-use cosmetics. This is not an easy task for formulators to accomplish. Keeping the rheology properties in check while ensuring the formula stability without compromising on aesthetics is already difficult, not to mention labelling the formulation ‘natural’. This was the reason formulators started looking for multifunctional natural ingredients that would fulfil these requirements.

While most ingredients used in personal care formulations have one or another function, smectite clays such as Veegum (INCI: Magnesium Aluminum Silicate) or Vanatural (INCI: Bentonite Clay) have the desired properties to be truly multifunctional ingredients. Both lines of products contain blends of montmorillonite and saponite ores, so the properties of Veegum and Vanatural are as unique as individual smectite clay types themselves. Since no harsh chemicals or additives are used during the beneficiating process, just clean water technology, these products are as pure as nature made them. They disperse easily, hydrate rapidly and perform constantly to:

• stabilise emulsions against separation, particularly at elevated temperatures

• stabilise suspensions against particle setting and hard packing

• provide thickening and absorptive properties in face, hair and body masks

• have high electrolyte and surfactant compatibility

• provide a silky, tack-free feel in topical preparations

• be synergistic with common thickeners such as xanthan gum, CMC, acrylates and carbomers

• reduce the sticky feel of gums and polymers

• be compatible with anionic and nonionic ingredients used in personal care formulations.

Natural, eco-friendly and waterless formulations

Vanatural bentonite clay is perfectly suited for use in all-natural and organic-labelled personal care and baby products. Vanatural and Vanatural XGB (INCI: Bentonite Clay and Xanthan Gum) are Cosmos and Ecocert approved. Vanatural MC is a micro-controlled grade for those who like the INCI name bentonite clay but prefer a controlled bacterium count in their raw materials.

Bentonite clays from Vanderbilt Minerals, LLC are recommended for use in skin renewal creams, hydrator lotions, high-SPF sunscreens, baby products, foundation makeup, hair treatments, face masks, body washes and shampoos, as well as in liquid and solid soaps and trendy shampoo bars.

Vanatural bentonite clay enables the formulation of consumer-friendly, just-add-water personal care products. These are reconstitutable blends of powder-form ingredients made functional simply by adding a small amount of water or another liquid just prior to use. These formulations are great for travelling without the excess weight of water. No preservatives are needed and their shelf life is virtually unlimited. In reconstitutable products, Vanatural swells quickly, imparting a creamy texture. It also stabilises the foam structure in cleansing products and serves as film-forming binder and an absorbent in facial masks.

For more information on how smectite clays work and how to use them, please visit the Vanderbilt Minerals, LLC website. Access to all literature, videos and prototype formulations is free and all documents are download-ready. For local assistance, please contact the distributor for South Africa, IMCD. •

VANATURAL and VEEGUM are registered trademarks of Vanderbilt Minerals, LLC.

IMCD – www.imcdgroup.com

Vanderbilt Minerals, LLC – www.vanderbiltminerals.com