What are clays?
Earth. Literally. Clays are geological minerals formed over millions of years by the erosion of silicate rocks. They are found in soil layers all over the world, though not all clays are the same or serve the same purpose.
They have been used in cosmetics since ancient times. Egyptians, Greeks, Berber peoples. Without knowing anything about chemistry, they already knew that clay cleaned, soothed, and improved the skin. Today we know why.
How they work
Clays have a microscopic lamellar structure with a negative electrical charge on their surface. This charge attracts positively charged particles: sebum, dirt, dead cells, toxins, bacteria. They adsorb them, not absorb them, they adhere them to their surface, and when you rinse, they wash away with the water.
Additionally, depending on the type, they can provide minerals to the skin, stimulate microcirculation, or have a soothing action. It's not just cleansing; it's active mineral exchange.
A general rule: the more color, the more potency and more minerals. White and pink are the gentlest; green and red are the most intense.
The clays in our products, one by one
Kaolin
The finest and most delicate. It cleanses without aggression, absorbing just the right amount of excess sebum without stripping hydration. It's found in products for sensitive, dry skin, and even in baby products. In solid shampoos, it adds body and softness without drying. This is the clay that convinces skeptics.
In the INCI: Kaolin
Green clay
This group includes several varieties, illite and montmorillonite, with a mineral profile very rich in silica, magnesium, calcium, and potassium. It deeply purifies, absorbs excess sebum, stimulates circulation, and has antibacterial action. For combination and oily skin, it's the go-to option. Used alone, as a mask, about 10-15 minutes are sufficient; more time will unnecessarily dry out the skin.
In the INCI: Illite, Montmorillonite
Montmorillonite
Its name comes from Montmorillon, a town in central France where it was first identified in the late 19th century. The geologist who described it named the mineral without knowing he was baptizing one of the most used ingredients in natural cosmetics of the following century.
It belongs to the smectite group, clays with a very expandable lamellar structure that absorbs large quantities of water and molecules between their layers. This capacity is what makes it so effective: it traps impurities, sebum, and toxins with superior efficiency compared to other clays. It is the main active component of many commercial green clays. For combination and oily skin prone to imperfections, it is one of the most complete options.
In the INCI: Montmorillonite
Ghassoul
Volcanic clay from the Atlas Mountains, Morocco. Its name comes from the Arabic "ghassala," to wash, and it has been a protagonist in Maghreb hammams for centuries. It is one of the few clays with such a well-documented and continuous history of cosmetic use.
Rich in silicon, magnesium, potassium, and calcium. It absorbs impurities without stripping natural lipids, cleansing without drying. It works equally well on skin and hair, tolerated by skin types that cannot handle green clay. Purification without aggression.
In the INCI: Ghassoul, Lava Clay
Pink clay
A natural blend of red and white clay. It purifies more gently than green clay, provides minerals, and has a soothing effect. Ideal for normal or combination skin that doesn't need heavy artillery but wants something more than kaolin. It also works well in hair products to balance without aggression.
In the INCI: usually appears as Kaolin (pink) or a blend of red and white clays
Red clay
The most mineralized. Rich in iron, hence the color. It stimulates circulation, has an intense purifying action, and is the most suitable for skin with imperfections, blackheads, or pronounced excess sebum. It is not for daily use or for dry skin. Use it as an occasional treatment and observe how your skin reacts.
In the INCI: Illite (red), Red Clay
White clay
Similar to kaolin in gentleness, but with greater purifying capacity. It cleanses without drying, soothes redness, and is well-tolerated by reactive skin. Widely used in oral hygiene products for its gentle cleansing action and mineral contribution.
In the INCI: Kaolin (white), White Kaolin
Use and integration into your routine
As a facial mask: mix with water, hydrosol, or aloe vera until a paste forms. Apply to clean skin, leave for 10-15 minutes, do not wait for it to dry completely as it will then dry out the skin, and rinse well. Once or twice a week is sufficient.
In cleansing products: solid shampoos, facial cleansers, exfoliants. Here, the clay works during the contact time of washing, brief but effective.
In toothpaste: kaolin and white clay gently mechanically clean enamel without aggressive abrasives and provide minerals. One of the reasons why natural toothpastes work better than people expect.
Combines well with argan oil to counteract the drying effect on combination skin, and with niacinamide and hyaluronic acid in the same day's routine.
Curiosities and facts
The name comes from Chinese
Kaolin derives from Gaoling, "high ridge," the name of a mountain in the Chinese province of Jiangxi where it was extracted to make fine porcelain. The same clay that gives smoothness to Ming porcelain is what you find in your facial cleanser. Not bad.
Adsorption, not absorption
The difference matters: to absorb is to incorporate something into the interior (like a sponge with water); to adsorb is to retain something on the surface by electrical attraction. Clays adsorb, which is why they cleanse without penetrating the skin. Physics does the work.
Mud masks are not the same
Mud mixes clay with organic matter and dissolved minerals. The properties are similar but more difficult to standardize. Cosmetic clays are purer, more predictable, and easier to formulate. Dead Sea mud is the famous exception; its mineral concentration is so high that it has its own category.
Green isn't always green
Green clay owes its color to the presence of ferrous iron and organic matter. If you see powdered green clay that looks too uniform or bright, there may be dye involved. In natural cosmetics, the color should come from the mineral, not the dye.
Clays do not expire
Technically, a geological mineral has no expiration date. What can degrade is the product formulated with clay if it contains other active ingredients. Pure powdered clay, well preserved and dry, lasts indefinitely. It has been waiting for millions of years; a few more years on your shelf won't affect it.
As it appears in the INCI: Kaolin, Illite, Montmorillonite, Red Clay, White Kaolin
Other active ingredients you might be interested in
Syndets: the gentle surfactants that accompany clays in many of our solid products.
Argan Oil: to restore hydration after a clay mask.
Jojoba Oil: sebum-regulating, ideal in the same routine.
Niacinamide: to complete the purifying work with action on pores and sebum.
