How can one tell when a coin has been cleaned, especially if it was cleaned long ago?
If the coin has been cleaned with an abrasive, the coin will have hairlines. Have a look at the coins in Overton’s half dollar book; a large proportion (maybe 20%) of them appear to have been harshly cleaned with an abrasive. Also, abrasive cleaning often leaves some crud in the recesses of the coin (untouched dirt or left over abrasive). If the coin has been dipped, it may or may not be detectable. A bright white 1801 half dollar is immediately suspect. Although it is possible for such an original coin to exist, it is unlikely. Also dipping can strip the lustre off of the coin, with the end result that there is no lustre where you would expect it to be for a coin in said condition (XF and better coins). A natural coin has a particular appearance which reflects the history of its storage. Haphazardly stored coins tend to have a “dirty” appearance to the toning. Coins that have lived for a long time in a coin cabinet tend to have spectacular colored toning. Coins stored in a clean metal
