Two weeks ago I purchased 6 X 1937 crowns in cardboard holders, all looked good except one with a bad mark on it which I decided to clean, as soon as I broke it loose it was obvious it was to thin to be real so, out comes my 1 kilo magnet and lucky me, there were 2 fakes. Although I know who sold them to me, eBay does not want to know about it. So now I use the magnet before opening any package of silver from an unknown and if I get a reaction it will go direct to the police and they can open it.