Montana Bentonite IS calcium bentonite: The Healing Clay, The Living Clay.
This clay was organic before we were organisms. This was the bio-available base from which all life evolved. Calcium bentonite provided the mineral environment to feed all life development here on planet Earth.
Calcium Bentonite, the "Mineral of a Thousand Uses" is the original bio-available organic, chelated and colloidal mineral clay. Click for details>>