Toning is a chemical process that either increases or decreases the value of a coin. This occurs naturally over time, this is the result of sulfur and oxygen reacting with the metal of a coin. The process accelerates with the mixture of moisture and heat, and may affect coin values.
Some of the characeristics of a toned coin are:
- Copper - orange to reddish brown to full brown or black.
- Nickel - silverish color to musty gray.
- Gold - reddish color or bright yellow to orange.
- SIlver - sometimes it has a rainbow-like color or bright silver to black or brown.
Artificial Versus Natural Toning
Coins that have a natural toned color are the result of a slow and long process wherein chemicals in the environment affect a coin’s surface. Morgan dollars are an example of coins that have vivid colored toning; they are also one of the most popular coin series in a coin collection.
Many of the Morgan dollars got their tone because of the way their owners stored them over time. Some of these coins were in storage for more than a century in canvas bags in vaults. The chemicals found in the cotton bags reacted with the coins and resulted in a rainbow-tinged tone over time.
Some coin folders and albums, and paper envelopes that are not archive quality material may have acids and sulfur that will affect a coin’s surface. This chemical reaction may result in beautiful toning or black and ugly brown toning, which affects coin values.
You may encounter coin doctors who will use certain chemicals to produce rainbow toning on coins artificially. They may also use toning to hide alterations or imperfections on the coins they want to trade or sell. Coin dealers or grading companies will be able to detect this quickly.
Visual Appeal
A toned coin may attract two different perspectives; some collectors prefer coins with a beautiful rainbow-tinged surface. They will pay a high price above the value of an un-toned graded coin. Other collectors prefer a shiny, old coin because they believe that the tone is surface damage, decreasing its collector value.
Toned coins have their appeal, depending on who is looking, however, ugly, brown, black or deep olive green tone that is uneven will have a negative effect on the visual appeal of that coin.
Effect on Value
Coin values are important to collectors; the market for toned coins is high and collectors will pay a premium to get their hands on them. Coins that have vivid colors and come in a gamut of differing hues will have a positive effect on its value.
Toning may make a common low-value coin a must-have for a collection. A scarce or rare coin that has an attractive and natural tone will fetch a hefty price from an avid collector. As the cliché goes, beauty is in the eye of the beholder. It is difficult to pinpoint whether toning has a positive or negative effect on a coin’s value.