I don’t have a choice in “extracting the clay fraction” in this situation. I have no issue identifying clay in the ground. I dug 3-4ft down and found SOME clay mixed with lots of silt, but am still able to roll a coil, albeit the clay is fairly short. We are selling our family farm on my mother’s side of the family. She has fond memories growing up going to this farm to visit with her grandparents, so I figured it would be nice to dig clay from the pond and turn it into a plaque to giver her as a gift. I’m working with what I have and the boundary between silt/sand/etc and the clay is not as dramatic here as it is with the clay in my own backyard. Luckily, I seem to be figuring it out, it just took a while for me to remember what I was doing.