Welcome to T Net, that said, is it magnetic? How large is it? Where did you find it? Along a creek, ocean, lake? What country might also help. Being heavy like lead would rule out melted aluminum, but that's why I asked the country or state, because in Oregon, the weather usually isn't such that people sun bathe on blankets at the beach. But they go to the beach and build lots of driftwood fires where people sit around them, drink beer and throw the empties in the fire, hence a lot of aluminum nuggets to be found here.