Today at the nashville show I nearly bought a beautiful "starting to tone" braided hair large cent from a dealer I trust & have dealt with for several years, when he volunteered that the coin had been cleaned long ago & was now beginning to tome over. I passed on the cent (but appreciated the dealer's honesty & bought several other coins from him), but now.... How can an american modern coin newbie learn how to detect prior cleaning?? I have been dealing with ancients for several years now & ALL of them have been at least partially cleaned during the past 2000 years, but I understand it is a bad thing for modern coins. Thanks, Bill
Excellent question Bill. If a coin has been harshly cleaned you're gonna notice "hairlines". If a coin has been overly dipped, you will notice some impaired luster. That's the quick answer to your question. I'm sure some more knowledgeable members will chime in with some more clues as to how to detect a cleaning.
It is possible to learn the elements of detection by photos and descriptions, but it is extremely limited. You really have to have coins in your hand that you know have been cleaned to learn. My imperfect suggestion is to get a group of early Lincolns of various grades , from gunky ones to BU ( probably late 50's) and clean them yourself with every thing from a distilled water or acetone rinse ( both should be non-detectable as they have no physical action on the coin) , to the harsh scrubber and vinegar. Careful observation of before and after will do more than just reading about it. Look for physical scratches or line, changes in the patina, lighter or darker spots where debris was before removal, differences of debris in the tighter spaces ( inside of letters like "e" or numbers "9" ), toothpick or thorn scratches inside the device areas. Sounds like a lot, but once it starts to hold in your brain, you can spot it almost immediately. The gemology training schools for their online courses of gem identification and "enhancements" use to send a "lab box" of labeled specimens to identify and spot for a grade. It is too bad that ANA or even a commercial firm doesn't do the same for grading, counterfeit identification, cleaning and alteration, etc. IMO. Jim