rust chips and rocks!............ but don't feel too bad, keep everything you find and check it when you get home. many people have thrown good items back into the sea or into the trash not knowing what they had was actually good but looked like junk. those rust chips you find, especially any black colored ones might turn out to be a cob and not a rust chip. check all finds like that at home with a magnet like southern digger said, I do exactly that.