Dredge tailing piles are full of crap, can, barbed wire, nails, hot rocks etc. Was hunting in Idaho, After digging countless targets you think another iron chunk, but I dig everything regardless of sound. This one come in rather loud and was setting a flat rock about 5" deep. Biggest nugget I have found. Weighed 5.56 ounce. Found a few years back and traded for a S&S 91/2' pickup camper, Now that nugget is worth a whole lot more and the camper has ;lost 3/4 of it's value. Oh well life goes on.