Bentonite is used as a drilling mud when drilling oil or gas wells. I worked my way thru college by working in the oil patch during the summers. While tying in a gas line to a newly completed well (gas lift well) we experienced a fire. Naturally we all ran in different directions. One of my coworkers got about 3 good strides into an old pit containing bentonite and cuttings from an old well. That pit was 5 or 6 years old. It had a 3 or 4 inch crust on top but under that the bentonite was just like the day it was put there. He sank in above his hips. That stuff is slick.
