It is more like that is a sort of drilling mud (bentonite possibly additioned with baryte ): https://en.wikipedia.org/wiki/Bentonite https://en.wikipedia.org/w

It is more like that is a sort of drilling mud (bentonite possibly additioned with baryte ): https://en.wikipedia.org/wiki/Bentonite https://en.wikipedia.org/wiki/Bentonite https://en.wikipedia.org/wiki/Drilling_mud https://en.wikipedia.org/wiki/Drilling_mud Bentonite is also used in medicine (dermatology).