That's a very good idea. I have a lot of counterfeits in my collection. Some are so good I could easily pass them off and no one would ever be the wiser. On the other hand some are so bad it's amazing they were ever accepted by anyone. I have been slowly getting them all catalogued for my own personal information. I have an xrf scanner and break them down by composition, weight, diameter, and magnetic or not. At the local coin shows all the regular dealers know me and they pull their bogus coins for my collection. I also take the XRF with me and every show I find a few that people are trying to sell are counterfeit. The dealers will tell them it's a counterfeit yet the person is sure it's real and the dealer is trying to "rip them off". When you pull out the scanner and show them their "silver" coin is 90% tin they stop arguing.