Much fine gold and flakes trapped in the rocks. I cracked open one rock that had a chunky little picker in it and a few flakes much fine. I cracked about a dozen after that and while the first one had the best signal every rock had fines in it. I was just cracking rocks with signals. I tried every type of rock That had any signal just to see. Red rocks, concrete stuff, caliche, porous rocks, quartz and others. I still have a dozen or so left to crack up. But all I have is my sledge hammer and a shirt so not even crushing very fine about 1/4” to 1/8” I kept the tailings for a later date when I might have a better crushing method.