Quaternium-90 Sepiolite and Quaternium-90 Montmorillonite (Thickening Clay)

What is it? Quaternium-90 Sepiolite (and) Quaternium-90 Montmorillonite (Thickening Clay) is an alkyl quaternary ammonium clay. It’s basically a fine powder derived from clay that has been treated to create a powder that, when used in small amounts, thickens oil-based products and helps keep pigments in suspension. It is generally recommended for use in cosmetics.

This product is manufactured by Eckart America and is called GARAMITE-7308 XR.

While this product certainly helps prevent pigment settling, it does not prevent it entirely. Too much can make products feel dry on the skin, so simply using more isn’t always a good approach, either.

INCI Quaternium-90 Sepiolite (and) Quaternium-90 Montmorillonite
Appearance Off white fine powder
Usage rate The suggested rate is 1–3%
Texture Smooth ultrafine powder
Scent Nothing noticeable
Charge Cationic (positive)
Solubility Insoluble
Why do we use it in formulations? Quaternium-90 Sepiolite (and) Quaternium-90 Montmorillonite does four very cool things. 1) It thickens oil-based concoctions. 2) It contributes to a more matte finish. 3) It helps keep powdered pigments in suspension. 4) It helps improve adhesion/wear time in colour cosmetics.
Do you need it? If you like creating coloured cosmetics I would highly recommend it!
Refined or unrefined? Quaternium-90 Sepiolite and Quaternium-90 Montmorillonite only exists as a refined product.
Strengths Excellent pigment suspension, thickening, and skin feel at low concentrations. It’s also very easy to work with!
Weaknesses Too much can make the end product drying (I find even 3% can create products that are more drying than I’d like, especially in lip products). It’s also pretty dang hard to source outside the USA.
Alternatives & Substitutions I don’t have any great recommendations. You can try using white kaolin clay in its place, but this will not have the thickening/suspending properties or the added adhesion.
How to Work with It Take care not to inhale the clay—wear a dust mask. This product is very lightweight and floaty, and very easy to accidentally inhale. Stir/blend it into the oil phase of your concoctions at pretty much any point—the manufacturer stipulates it can be incorporated at any time. Low shear mixing is sufficient—I usually use my MicroMini Mixer to blend everything together.
Storage & Shelf Life Stored somewhere cool, dark, and dry, Quaternium-90 Sepiolite and Quaternium-90 Montmorillonite should last at least five years.
Tips, Tricks, and Quirks Learn more about Alkonium Clays here.
Recommended starter amount 30g (1.06oz)
Where to Buy it The only place I’ve found it for sale is TKB Trading.

Some Formulations that Use Quaternium-90 Sepiolite and Quaternium-90 Montmorillonite (Thickening Clay)

Rhassoul (ghassoul) clay

What is it? Rhassoul (also known as ghassoul, or sometimes Moroccan clay) clay is a highly absorbent naturally occurring clay that is mined in the mountains of Morocco. It is made mostly of silica and magnesia.
INCI Moroccan Lava Clay
Appearance Fine brown powder
Usage rate Up to 100%
Texture Rhassoul clay is quite sandy, which makes sense given it is mostly silica and so is sand! The coarser grades have larger particles, but I’ve found all grades to have a distinct sandy feel to them.
Scent A bit dusty
pH 6–9
Solubility Insoluble
Why do we use it in formulations? It makes for a lovely, absorbent, gently exfoliating face mask on its own or blended with other clays (and some kind of liquid, of course!). It is also a nice addition to cold process soaps and anhydrous exfoliating and/or cleansing balms.
Do you need it? No, but it is quite unique among the clays. I’d probably get a small amount to have on hand as it’s inexpensive and has an extremely long shelf life.
Refined or unrefined? Rhassoul clay can be purchased at different levels of fine-ness; I would recommend fine over coarse.
Strengths An excellent absorbent and mildly abrasive clay—the favourite of many.
Weaknesses I can’t think of anything inherent to rhassoul clay, but clays often come down to being personal preference. I tend to prefer creamier clays, like French green or kaolin, as rhassoul is more sandy/mealy.
Alternatives & Substitutions Rhassoul clay is unique among clays for its sandier texture. Clays like French green and kaolin are much softer and creamier, while bentonite is significantly more absorbent and hydrates into a gel-like paste. I’d probably try a blend of 2 parts kaolin to 1 part bentonite as a starting point.
How to Work with It For a mask, whisk small amounts of rhassoul into whatever liquid is in the recipe, ensuring the mixture is smooth before adding more. In soap, blend in the clay with an immersion blender when required by the recipe (typically either into the oils or lye water before combining, or into the batter at trace).
Storage & Shelf Life Stored somewhere cool, dark, and dry, rhassoul clay should last indefinitely.
Tips, Tricks, and Quirks Rhassoul clay has a long history of being used to wash the hair and body by North African women.
Recommended starter amount 100–200g (3.3–6.6oz)
Where to Buy it  Buy it from an online DIY ingredient supplier or Amazon.

Some Formulations that Use Rhassoul (ghassoul) clay

Fuller’s Earth/Multani Mitti clay

What is it? Fuller’s Earth/Multani Mitti clay is a naturally occurring clay. It has long been used in skin care as a brightening and purifying face mask. It also has a history of use in wool production, being used to remove oil from the wool as it’s a great oil absorber.
INCI Fuller’s Earth
Appearance Cream to beige fine powder
Usage rate Up to 100%
Texture Smooth, fine powder
Scent A bit dusty
Solubility Insoluble
Why do we use it in formulations? Fuller’s Earth/Multani Mitti clay can be combined with liquid to create a face mask. It can be used as a mild physical exfoliant/abrasive, and can be added to soap to make it creamier.
Do you need it? No
Strengths Simple, smooth clay with a long history of use.
Weaknesses I haven’t been particularly taken with it over any of the other clays.
Alternatives & Substitutions I’d use kaolin clay instead as my first choice. After that, another smooth clay like French green clay would be a good choice. I would not use bentonite clay instead.
How to Work with It Take care not to inhale large amounts of Fuller’s Earth/Multani Mitti clay. When blending with liquid I recommend adding small amounts of clay to the liquid, whisking until smooth before adding more clay. Add at trace in soap making (start with 1–2 tbsp/500g of oils).
Storage & Shelf Life Stored somewhere cool, dark, and dry, Fuller’s Earth/Multani Mitti clay should last indefinitely.
Tips, Tricks, and Quirks Fuller’s Earth/Multani Mitti clay has many non-DIY uses, including cat litter and a poisoning treatment!
Recommended starter amount 100g (3.3oz)
Where to Buy it  Buy it from an online DIY ingredient supplier or Amazon.

Some Formulations that Use Fuller’s Earth/Multani Mitti clay

Bentonite Clay

What is it? A heavy, fine grey clay (Calcium Bentonite).
Appearance A fine grey powder with light and dark flecks.
Texture Smooth and dusty.
Scent Dusty and rather unremarkable.
pH ~9
Solubility Insoluble
Why do we use it in formulations? It’s a strong clay that’s amazing at cleaning out pores.
Do you need it? Bentonite is pretty weird—some people love it and some people don’t. I could live without it.
Strengths It’s a very strong clay with a really unique texture when it gets wet—it gets all jelloid and is way more absorbent than other clays.
Weaknesses It has a high pH that can irritate more sensitive skin.
Alternatives & Substitutions It’s really unique and weird; it’s not a good substitute for other clays, and other clays are not a good substitute for it.
How to Work with It I mostly use it for face masks.
Storage & Shelf Life Stored somewhere cool, dark, and dry,
Tips, Tricks, and Quirks Check out this experiment to learn about how absorbent and weird it is!

You’ll commonly read that bentonite clay should never, ever come into contact with metal because it carries a charge. This is not true.

Recommended starter amount 100g (3.3oz)
Where to Buy it  Buy it from an online DIY ingredient supplier or Amazon.

Some Formulations that Use Bentonite Clay

French Green Clay

What is it? Pale green, smooth Illite clay that’s mined in France. It is mostly illite clay with some kaolinite and smectite.
INCI Illite
Appearance Fine, pale green powder.
Usage rate Up to 100%
Texture Smooth and light when dry, smooth and creamy when mixed with water.
Scent Nothing noticeable, perhaps a bit dusty.
pH 7.75
Solubility Insoluble
Why do we use it in formulations? I mostly love it in face masks—I’ve found it really agrees with my complexion and is brilliant for purging pores without being too drying. I’ll also include it in soap as clay in soap makes for a lovely creamy bar, but it’ll also turn the soap green, so I’ll only use it if I want the final soap to be green.
Do you need it? Only if you’re a face mask junkie; like most coloured clays this one isn’t terribly useful if you don’t love it for face masks.
Strengths Fantastic for face masks if your skin likes French green clay (USA / Canada).
Weaknesses Not hugely useful for much else.
Alternatives & Substitutions It’s reasonably easily substituted for other French clays and other light, smooth clays like kaolin or zeolite.
How to Work with It As French green clay (USA / Canada) is a fine powder, be sure to wear a dust mask around it if it’s going to become aerosolized (like if you’re whipping it up in a coffee grinder).
Storage & Shelf Life Stored somewhere cool, dark, and dry, French green clay (USA / Canada) will have an indefinite shelf life.
Tips, Tricks, and Quirks When blending French green clay (USA / Canada) into a liquid, slowly whisk it into water (as opposed to adding water to the clay) for the smoothest possible blend.
Recommended starter amount 100g (3oz)
Where to Buy it  Buy it from an online DIY ingredient supplier or Amazon.

Some Formulations that Use French Green Clay

Kaolin Clay

What is it? Kaolin clay is a fine, smooth clay that comes in a variety of colours (white, red, green, pink, yellow, and orange). I tend to use white 99% of the time I use kaolin.
Appearance A light, fluffy, fine powder.
Texture Smooth and creamy when blended with water. Light and smooth when dry.
Scent A bit dusty? Nothing terribly noticeable.
pH 6
Solubility Insoluble
Why do we use it in formulations? It’s a great all-purpose clay; in terms of strength it’s pretty middle-of-the-road, making it great for face masks for all skin types. I also love the white stuff in cosmetics and body powders as it helps boost adhesion and manage moisture.
Do you need it? If you were only going to purchase one clay, I’d recommend white kaolin.
Strengths Kaolin is extremely versatile and is a fantastic all-around clay.
Weaknesses If you’ve got very oily skin you might find white kaolin clay (USA / Canada) isn’t strong enough for you.
Alternatives & Substitutions Other light clays (the French clays, zeolite) can work similarly well in face masks and soap. In anything where you need your clay to be white, white kaolin is your best choice by a mile.
How to Work with It As kaolin is a fine powder, be sure to wear a dust mask around it if it’s going to become aerosolized (like if you’re whipping it up in a coffee grinder).
Storage & Shelf Life Stored somewhere cool, dark, and dry, kaolin has an indefinite shelf life.
Tips, Tricks, and Quirks When blending kaolin into a liquid, slowly whisk it into water (as opposed to adding water to the clay) for the smoothest possible blend.
Recommended starter amount 100g (3oz)
Where to Buy it  Buy it from an online DIY ingredient supplier or Amazon.

Some Formulations that Use Kaolin Clay