What is Coin Toning? How Does It Affect Coins and Their Value?

by CoinNews.net on September 3, 2007 · 4 comments

Silver dollars at varying levels of toningCoin toning can intrinsically increase or decrease the value of coins. Natural coin toning can be quite beautiful. It can also be outrageously ugly.

And because beauty is often times in the eye of the beholder, placing a value on a coin due to its toning can present problems.

Should you pay extra or less for toned coins? After all, a coin that’s toned is going through a form of corrosion, right?

What exactly is coin toning?

Toning is a term that describes the discoloration or light patina that forms on the surface of coins due to oxygen and chemicals in the air acting on the metal. This oxidation can result in a variety and level of toning and also depends on the properties of the metal – silver, gold, copper, nickel, etc.

Toning is a slow and normal process that can take months to years to appear. Should you worry about toning? If you’re storing your coins properly, don’t. Unless a coin is in a vacuum, it’s going to start at some point.

A coin that’s toned is in a normal "stage" of its life. It won’t disintegrate away before your eyes. Even in worst cases, the tone color will normally take centuries to reach its very darkest and usually its least attractive appearance.

In fact, you’ll hear coin collectors use the word toning often to a describe a coin’s natural and appealing discoloration.

We’re all familiar with tarnishing. Tarnish and toning are pretty much synonymous on the scientific scale. However, it’s more typical to hear that a coin is tarnished when describing one that appears discolored in an unnatural, spotted or artificial way.

How can you tell whether coin toning adds value to a coin?

There are several factors in determining the value of a coin, but at the very top for most people is its appeal. If a coin is ugly, unless extremely rare, people aren’t going to buy it and the value will be low. If a coin is attractive AND toned, it’ll likely be worth more.

But again, beauty is in the eye of the beholder. With that fact in mind, does it basically imply there’s a smaller market for toned coins? One could argue when there’s no other differentiation, a lustrous coin that looks like new will always have a better market reach and potential than a coin with attractive toning.

Of course, there’s the flip side of the argument. If coin collecting was all about shiny coins, collectors would have much less resistance when it came to buying cleaned coins. We know that’s not the case!

With all things considered, a coin’s value is always going to be higher when it’s NATURALLY attractive. Historically, beautifully toned coins that are older garner a premium. It’s not just beauty that sets them apart but their uniqueness.

Why? A shiny coin is a shiny coin. Everyone’s seen one. A toned coin that’s also attractive, however, isn’t something you see every day. A coin that is both unique and attractive is one that’s sought after by most experienced collectors. They’re rarer and, therefore, worth more money.

What coin toning colors should you expect to see?

As we first discussed, toning and its color will depend on a coin’s metal composition. Older coins can show more color variations due to multiple and less pure metal "blends". And metals like copper and silver can react more quickly and often times tone easier when exposed to the environment.

Here are some very general toning characteristics of the major metals in coins we know today:

  • Copper – The life cycle you’re most typical to see is orange to reddish-brown to full brown to nearly black.
  • Nickel – Silver-ish to eventually a musty gray.
  • Silver – Bright silver to brown to black. Sometimes rainbow-style colors appear in the toning of silver, which can really add to value.
  • Gold – Bright yellow to orange. Sometimes a reddish color.

Beware of artificially toned coins

Unfortunately, just as toning happens naturally with coins, it can also be mimicked artificially by "coin doctors". (Think of coin doctors as forgers.) If you Google the words "tarnish silver" for example, you’ll find "recipes" for ways to create a tarnished look on silver.

Why would anyone try to artificially tone a coin? It’s nearly always an attempt to improve a coin’s appearance so it can be sold for more. It’s not just to try and seek the premium dollars paid for gorgeously toned coins. More often than not, it’s to hide imperfections the coin already has.

In ANY instance or method applied to a coin to doctor its appearance, the value of the affected coin IMMEDIATLY declines SUBSTANTIALLY. You don’t want to buy them!

It usually takes some experience to recognize a coin has been artificially altered. If you don’t have that experience and you’re interested in a coin due to its toning, be cautious on how much you spend for it.

Ideally, buy significantly priced and toned coins that have already been graded by a third party grading/certification service, like PCGS (Professional Coin Grading Service) and NGC (Numismatic Guaranty Corporation).

If your coin has gone through a grading service, you’ll at least have some protection. The last thing you want is to pay for what you think is a gorgeous coin only to later find out it was doctored, making it worth little.

{ 4 comments… read them below or add one }

Dana October 19, 2010 at 2:49 pm

I have a Georgia quarter with obverse having a swirl of light black. It seems as though it is mixed with the metal. On the reverse it is a darker black over the whole area. Do you think this is discoloration or possibly an error?

Anthony August 10, 2013 at 3:18 pm

I have two american eagle silver dollars accompanied by a certificate of authenticity. I received them in mint condition but then after three months, they have both tarnished with a distinctive tarnish line running across of both faces of each coin. Both issued by the New York Mint. Will they replace these?

skylar January 21, 2014 at 5:31 pm

put a silver dollar on my roof four a couple of years u think it will look cooler

Bruce Whalen January 30, 2015 at 12:25 pm

I use to be a pipe fabricator. I have worked with many types of metal up to titanium and you stated …After all, a coin that’s toned is going through a form of corrosion, right? . If you are asking a question or making a statement your wrong. Not all metals corrode. The more higher grades don’t unless they are contaminated with other hot temp. metals that come in contact with them. Grade of the metal makes a big difference like 316 stainless steel can be touched and set out in the air for a long long time and still keep its shine. I think that American made silver coins contaminate easily because its only 90% silver. I fit Titanium and if the oxygen is present it tones and it very pretty but it will not pass inspection and it turns that pretty blue and red like you talk about.

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