I disagree.rrraven said:Montmorillonite clays are bentonite clays and bentonite clays are montmorillonite clays. They are not two separate minerals as we think.
Bentonite is a rock consisting of a mixture of different clay minerals, with a montmorillonite content of 60-80%. Bentonite usually forms from weathering of volcanic ash, mostly in the presence of water. The term bentonite have been used for clay beds of uncertain origin.
Montmorillonite is a very soft clay mineral, known for its agricultural value because it has a great water absorption capability.
The first time I heard of Montmorillonite was during my studies in Hesse (Rhein-Main Area), where many soils developed from Loess, an aeolian sediment with a high content of Montmorillonite. The fertility of the soil is so outstanding that when the Romans tried to protect their (occupied) territory against the Germanic tribes with a border rampart (the Upper Germanic Limes) they shaped it as a peninsula to include the "Wetterau" (a fertile undulating tract in southern Hesse) in order to use it as the breadbasket of occupied Germania (picture). At least that's the way we have learned it. Maybe the Romans had other reasons why this region rich in Montmorillonite was so important for them.
source:WikipediaMontmorillonite is also known to cause micelles (lipid spheres) to assemble together into Vesicles. These are structures that resemble cell membranes on many cells. It can also help nucleotides to assemble into RNA which will end up inside the vesicles and, under the right conditions, will replicate themselves . This might be the origin of life on earth.