And here are a few that I artificially toned. NOTE - I only artificially tone coins for educational and experimental purposes only, not to try and sell them which I consider to be fraud. I occasionally experiment with different techniques to make examples of AT coins to help teach people how to spot AT. Also, I recently made an AT vs. NT Exhibit for a coin design show. And here are pictures of the same coin taken approximately every 10 seconds as the coin was being artificially toned through thermal oxidation. Note the progression of colors as the oxidation film thickened. These are the easiest and most common colors found on artificially toned coins. They aren't usually this uniform, rather they tend to be splotchy or unevenly colored.