Toning (coin)
Toning on a coin is the change of colour brought about through oxidization, which forms a thin layer of tarnish on the metal's surface. Coin toning can vary in aesthetics, and thus can alternately add or detract from a coin's value.[1] Coins with unusual toning colours or patterns tend to be valued by coin collectors.
References
- ^ "What is Coin Toning? How Does It Affect Coins and Their Value?". CoinNews.net. Retrieved 20 October 2015.