Just for anyone who isn't aware, this is a better way to tell if a coin is fake than if it is real. If the weight doesn't match and it isn't significantly worn/damaged, then it's fake. But merely having the correct weight is no longer a confirmation that it's real unfortunately. Chinese fakers in the last decade have become skilled at creating non-magnetic alloys with weights close to silver. They make the coin out of that and electroplate it with silver, thus making size, weight, and silver tests all have the potential for false positives now. If it fails any of those tests, obviously it's fake. But even if it passes, if you suspect it may be fake, you'll need to check for other signs of counterfeiting (e.g., edge seams, small details on the coin not looking right, etc).