I came across this while looking through some rocks by water way close to my house in Northern California and I'm not sure what it is. I've taken it to a coin shop they try to tell me it was lead I've done as much research as I can online and cannot find any article or reference to let ever being marked with .83 3 the only things I have found are bullying but I'm not quite sure what I'm looking at whether it's a long-lost relic or just a fake can somebody possibly point me in the right direction if not give me some insight on how to possibly sell such aemmense piece of art and history. It weighs an incredible 58.8 lbs