A quick google search for tarnish defines “lose or cause to lose luster, especially as a result of exposure to air or moisture”. CoinNews describes toning as “the discoloration or light patina that forms on the surface of coins due to oxygen and chemicals in the air acting on the metal”.
Toning and tarnishing both happen from the same process of metal reacting with water, oxygen, and/or chemicals in the air to change the surface of the metal. But for a coin and precious metal collector, when is a coin tarnished and when is it toned?
The Eye of the Beholder
Much of the decision for whether a coin is tarnished lies in the viewer. Some collectors hate any changes in color to pure silver and will refer to any chemical changes as tarnished. Other collectors love toned coins and seek them out.
In general, toned coins will have an even and attractive coloring. Many collectors will refer to the “eye appeal” of a coin. This means that a coin, although tarnished, looks arguably better because of the change in color.
You can artificially tone coins; an experiment I have catalogued several times on American Coin Stash. If you are interested in artificially toning coins you should look at this article, where I toned coins with liver of sulfur gel, or this one where I toned coins with food from my kitchen.
If you hear a collector refer to a coin as ‘tarnished’ they are probably not impressed with the look of the coin. The coin may have uneven coloring, blemishes, fingerprints, or milk spots.
- “Milk Spots”
- Attractive, “Eye Appeal”
- Nice Colors (blue, purple, rainbow)
- Can Be Faked
Coin Denomination Matters
Certain coins are more likely to have attractive toning than others. Any coin with a high silver content which was circulated very little is more likely to have an attractive an even toning. Morgan and Peace silver dollars are coins which can often be found with toning. Since they have a high silver content, the silver reacts with oxygen and water often resulting in blue and purple hues. And, since the coins were rarely circulated, the toning comes out even across the coin since there were less hands to interrupt the process.
Coins that will develop less attractive toning or tarnishing are pennies and nickels. Pennies, composed of copper and zinc, are circulated too much to often have an attractive level of tarnishing on them. Nickels, composed of nickel and copper, usually only darken in color, rarely changing to the blues, purples, and reds people seek out in toned coins.
Not that it is impossible for any coin to develop an attractive tone. I have seen pennies turn really fantastic shades of blue and purple.
In the end, whether a coin is toned or tarnished, there is no clear line. Toning has become more popular in recent years which has driven the price of toned coins much higher.
With the increase in popularity, fakes have become more common. It can be hard to spot the different between natural toning, and toning that has been induced in a lab or kitchen. In fact, this is a great debate for collectors, “When does a coin become artificially toned?”
A coin collector could induce toning by leaving a coin in a hot attic for months or years, if done intentionally, does that count as artificial toning?
What do you think about toning? Share a comment below and vote in our poll!