Re: What does betanite soil consist of that makes it different from other soils

I beleive you are probably talking about bentoninte clays
Bentonite is a type of clay that belongs to the groups of clays called 
smectites.  These clays are known as 2:1 swelling clay
This means that the clay swells when it is wet and shrinks when it is dry
This makes bentonite very useful for lining ponds.  It swells and 
becomes nearly watertight when wet.

One company web page may offer some more info http://www.bhbentonite.com/