It’s a common question: What’s the difference between rhassoul clay and the other popular clays out there—namely, bentonite and kaolin clays? Well, many of the distinctions have to do with the source and makeup of the clay itself: “Most of the differences between the various clays depends on the location it’s derived, composition, and particle size,” says Robinson. “This variation can affect the color and mineral content.” (Read: Since Rhassoul clay comes from Morocco, it has a slightly different mineral content and trace elements than bentonite and kaolin, which stem from France and China, respectively.) 

And while all three options can effectively draw oil and impurities from the skin and scalp, they do so with varying degrees of absorption. Bentonite clay is the most absorbent of the trio, making it ideal for oily and acne-prone skin; rhassoul clay, with its honeycomb structure, is a happy middle ground—absorbent, but not too stripping (those with drier skin may find that bentonite clay draws too much moisture). Kaolin clay has the least absorption, Shamban notes, as the structure is fenestrated; that’s why kaolin clay “is one of the mildest options” to slather on skin, says board-certified dermatologist Lauren E. Adams, M.D. about clay masks. 

https://www.mindbodygreen.com/articles/rhassoul-clay