MINERAL

Montmorillonite (French Green Clay)

Montmorillonite

A naturally occurring green clay mineral that absorbs excess oil and helps skin look fresh, matte and clean.

Source

Natural clay mineral

Used for

Shine, oily-looking skin

How it works

A clay that lifts away shine.

Montmorillonite is a soft clay mineral formed from weathered volcanic ash, and the main mineral in the green clays often sold as French green clay. Its sage-green colour comes from the iron and other minerals naturally present in it. It is built from thin, stacked layers that take up water and swell, giving it a smooth, spreadable texture when mixed into a mask.

A review of clay minerals in dermocosmetic products describes how clays like montmorillonite are used both to build texture, thickening and stabilising formulas, and as absorbents that take up oil and impurities from the skin's surface. That absorbent quality is why clay is a classic base for face masks.

In a rinse-off mask it helps lift away excess oil and leaves skin looking fresh and matte. Clay masks are typically used once or twice a week, followed by a moisturiser.

01
A natural layered clay mineral, the main component of French green clay
02
Absorbs excess oil from the skin's surface
03
Leaves skin looking fresh, matte and clean after rinsing

Questions

What is montmorillonite?

Montmorillonite is a naturally occurring clay mineral that takes its name from Montmorillon in France. It is a very soft mineral made of tiny, scaly crystals in a layered structure. (European Commission CosIng; Handbook of Mineralogy)

What does montmorillonite do in skincare?

It does two main jobs. Clay helps thicken and stabilise creams and masks, and it absorbs excess oil and impurities from the skin's surface, which is why clay is such a classic base for face masks. Follow with a moisturiser. (European Commission CosIng; Moraes et al., 2017)

Is montmorillonite the same as bentonite?

They are closely linked but not identical. Montmorillonite is the mineral itself. It forms when volcanic tuff and ash weather and alter, and in doing so it creates beds of clay known as bentonite. Bentonite is therefore the name for these clay deposits. (Handbook of Mineralogy)

Where it comes from

Montmorillonite forms naturally as volcanic tuff and ash weather and alter over time, creating beds of soft clay known as bentonite. (Handbook of Mineralogy)

Its crystals are tiny and scaly, and the mineral is very soft. Like other clay silicates it holds water within its structure, which gives it a smooth, spreadable texture when mixed into a mask. (Handbook of Mineralogy)

The research