Originally Posted by
coinnut
Tana, can't really tell by the pictures, but I would say it's just the normal corrosion, although the edges seem a bit eaten. Cleaning copper is the hardest thing to do because each piece is individual. So many different types of corrosion to deal with. If you ever get a chance, get a small jar of renaissance wax from Amazon (or any another place). A little goes a long way. If the coin is clean of most of the dirt, just let it dry well, and give it a small coating (especially the edges) and leave it be. It is a special one to you and you shouldn't be experimenting on that on. That is what Memorials and common Wheats are for lol I like the green patina on some coppers.