Was at a jewelers Shop last week. Happened to purchase an 1899 gold eagle from him while I was having my wife’s necklace repaired and I mentioned that any other pre-33 gold he acquired, please call me. He also had a 100 ounce bar of silver on his counter which was the spark that got me talking PM’s with the fellow. Today he called me and asked if I wanted that 100 ounce bar at spot. Personally, I prefer US mint issued rounds. They are numismatically interesting to me. But the thing that is most uncomfortable to me is that I would have no way of knowing how to authenticate a 100 ounce bar of silver. I believe I am going to politely turn his offer down. But if I have a weak moment and change my mind, how would a person authenticate something like that?