LisaLise's Guide to Cosmetic Clays


Clay is a fabulous and incredibly diverse ingredient to work with. Clays are great in masks, cleansers, color cosmetics – even emulsions and toothpaste (something we'll be getting into a little later on around here).

There are so many clays with so many different names that it can be hard for a clay-newbie (yes, that is an expression I just made up) to decide where to start.

Several of you have asked me for a quick overview of the most common clays used in skin and hair care products, so today – just for you – we're going to get down and dirty with clay!

LisaLise's Guide to Cosmetic Clays

  • Bentonite 
  • Diatomaceous Earth 
  • French Green Clay 
  • French Illite Clays 
  • Fuller's Earth 
  • Kaolin
  • Rhassoul 

Bentonite (INCI: Bentonite)

The INCI (Latin) name for this clay is the same as the common name (cool, huh?). Bentonite production is global with the US as the largest producer.

Bentonite is composed of smectite minerals (mostly montmorillonite) and volcanic ash. It got its name in around 1890 from a clay found near Fort Benton, Wyoming, USA.

Bentonite is a highly effective absorbent and adsorbent – so effective that you'll see it as a main component of many pet litter products. It is also used in numerous industries, including pharmaceuticals.

Bentonites ability to draw oil and impurities makes it a good choice for normal, oily, and combination skin types.

Bentonite can a bit difficult to work with on its own (read: it can be fiddly to get a good spreadable consistency if you're making a face mask). It becomes easier to work with (and more suitable for use with drier skin types) if it is mixed with kaolin.

Tip: there are many grades of bentonite (check the link below for an overview of uses). Be sure you are buying cosmetic grade when purchasing!



Diatomaceous Earth (INCI: Solum Diatomeae)

This is a commonly used ingredient in toothpastes, deodorants – and even some antiperspirants.

Diatomaceous earth is categorized as both abrasive and absorbent.

Composed of 80 - 90% silica, 5% sodium, 3 % magnesium, and 2 - 4 % alumina (also known as aluminum oxide), this sedimentary clay is mainly made up of different fossilized bits of diatoms.

Since you ask: diatoms are teensy weensy little water-dwelling organisms. So yes, you're applying a face mask of fossilized marine and freshwater algae with this product. That's actually a little cool, don't you think?

Diatomaceous earth can feel quite gritty and pumice-like on the skin – depending on the particle size.

Diatomaceous earth has a mattifying effect, making it a useful natural addition to some color cosmetics.

Diatomaceous Earth is available in several grades (even food grade) and a good choice for peeling masks and scrubs.

Mix it with kaolin for more sensitive skin types.




French Green Clay (INCI: Illite)

French Green Clay originates in Montmorillon (that's in France, but you already knew that part). And even though it is called French Green Clay, this clay is actually mined all around the world.

To thoroughly confuse the heck out of everyone, French Green Clay is also known as Montmorillonite, and sometimes even referred to as Sea Clay.

This clay belongs to the smectite group of minerals which describes how it is structured (2 pyramid-shaped 'sheets' of silica sandwiching an 8-sided layer of alumina).

Smectite clay minerals are super cool because of what they can do.

The individual crystals of this clay are structured in such a way that it has the ability to swell as it absorbs water – not just a little mind you. French Green clay can swell to several times its original volume.

The clay also boasts fab adsorbent properties, drawing out oil and impurities like a champ.

In short, it's an ideal clay for both masks and cleansers. The best part: it's well tolerated by all skin types, so you and your friend can double up on the mask mix and go green together.






French Illite Clays (INCI: Illite)

Illite clays come in several colors – each with slightly different characteristics. Some colors are achieved by different clays mixed together.

Normal skin types can use any of the Illite clays.

There's more about illite's properties just above, but let's take a brief peek at these 3 colors:

French Red Clay is a combination of kaolinite and illite with a deep red color due to its content of iron oxides.  If someone tries to tell you Moroccan Red Clay is the same as French Red Illite clay, feel free to correct them, because they are not at all the same thing. Look for superfine, cosmetic grade for your masks and cosmetics use. This clay is recommended for dull and tired skin.

Yellow French Clay - like Red Illite - is rich in iron oxides and boasts the same great adsorbant and absorbant properties of the other Illite clays. The Yellow clay is recommended for sensitive, dry, and mature skin.

French Pink Clay is a blend of kaolin with red illite. It is recommended for delicate and sensitive skin.  Read more about Illite under French Green Clay and more about Kaolin below.



Fuller’s Earth Clay (INCI: Solum Fullonum)

Fuller's Earth is any clay that has the ability to decolorize oil or other liquids without chemical treatment. (wikipedia)

It is typically either palygorskite or calcium bentonite, which may be why it was one of the earliest industrial cleaning agents.

Like bentonite, Fuller's Earth is a popular ingredient in pet litter products.

Fuller's Earth has excellent adsorbency, making it an ideal choice for oily skin types. Its ability to draw oil is effective to the point of being harsh, why it is It is recommended to mix this clay with kaolin or bentonite.

Fuller's Earth is also attributed with skin lightening and brightening properties and can be found on the ingredients list of many skin lightening products.

Fuller’s Earth is available in several grades. Be sure to purchase cosmetic grade.



Kaolin/White Superfine Clay (INCI: Kaolin)

Kaolin is an all-purpose clay with a wide range of uses and is therefore available in many different grades - from industrial to pharmaceutical. Always check that you are purchasing superfine cosmetic grade for use in your cosmetics.

Kaolin is rich in silica – making it ideal for dry and sensitive skin types.

Kaolin doesn't absorb nearly much as smectites or bentonite clay types, so you'll need a higher clay to water ratio to achieve the same consistency as with bentonite, rhassoul or illite.

Kaolin it is not amongst the priciest of clays which makes it a must-have for any cosmetics-making stockroom.

Kaolin imparts a lovely, silky feel to whatever it is added to.


Montmorillonite

This is the same as French Green Clay. See the section above for more details.





Rhassoul (INCI: Moroccan Lava Clay)

Rhassoul is known by several names: Ghassoul, Moroccan Red Clay, Moroccan Soap Clay and Moroccan Lava Clay. This clay is unique to one spot on the planet.

It is so multifunctional, it is quite simply a must have for any cosmetics stockroom. Rhassoul has the ability to cleanse both skin, scalp, and hair gently and effectively.

It is tolerated by even the most sensitive skin types.

Like montmorillonite, rhassoul has the ability to swell as it absorbs water, making it ideal for masks and cleansers. Rhassoul is available in chunk or powder form. The powdered form is easiest and most versatile to work with.

Tip: don't confuse this with French Red (Illite) Clay. Even though the 2 have similar properties, they are not the same.

There's an earlier post about rhassoul in more detail (with links to science-y nerdy stuff) right here.



A Few Clay Tips


  • Always store your clays DRY, in tightly closed containers and away from light.
  • Check the INCI name of the clay you are buying. That brilliant blue clay you just added to your shopping cart may 'just' be kaolin with a generous addition of color (not that that's necessarily a bad thing, but if you were expecting magical properties no other clay on the planet has because of the unique color, you might want to rethink your purchase).
  • When making a mask, sprinkle clay into water (not water into clay), and allow it to absorb the water all by itself before stirring to ensure a smooth, lump-free texture.
  • Remove a clay mask before it dries. Why? Because the clay only does its oil and impurity-drawing magic as it is drying. Curious to know more about the science behind clay masks? Check my fave post about clay masks and how they work by Colin right here.
Cosmetic analysis of Diatomaceous earth
French Green Clay for Healing
Montmorillonite (wikipedia)

Comments

Juanita Miglio said…
Hi Lisa,
What about the different colored Brazilian clays? Are they just kaolin with color added or do they come from the earth naturally colored?
Thanks
Juanita
Lise M Andersen said…
Hi Juanita - The colored Brazilian clays I have seen on the market are a mix of Montmorillonite, Kaolin and Mica. I have not yet come across a Brazilian clay that is different from any of the clays in this guide. Mind you, I'm always willing to learn, so if you have some sources to share, please do leave a comment! :)
This is an excellent guide. I was wondering if using superfine clays, like kaolins (3 microns
particle size) would be like using nanoparticles since probably the 3 micrometer is the average particle size and there could be some that are smaller. I can't find any information about this anywhere. What do you think about this?
Lise M Andersen said…
Hi SnowyOwl - Thanks for your input! Using superfine clays down to 3 microns is still not small enough to be classified as nanoparticles. 3 microns is equivalent to 3000 nanometers, so you're ok using superfine clays. Of course always be mindful of the dangers of inhaling powders. It's always a good idea to wear a mask when working with powders. :)