A Guide to Coin Toning
Coins have long been more than pieces of metal exchanged for goods and services, cherished not only for their monetary value but also for the rich history they carry. Among the various aspects that intrigue numismatists and collectors alike, coin toning is a fascinating element that adds an extra layer of beauty and character. But what is coin toning and how do you tell if a coin is toned?
This guide explores the process of coin toning to offer insight into why and how it occurs, and what makes it so alluring to collectors.
What is toning on a coin?
Toned coins are a result of a naturally occurring chemical process that changes the surface colour of coins over time. Often referred to as patina, this gradual development happens to any coin, although silver and copper coins are more susceptible to toning.
How does coin toning happen?
The process of toning can take hundreds of years and is primarily caused by oxidation of the metal’s surface. Exposure to oxygen and other gases in the air reacting with sulphur and other compounds causes thin layers of metal oxide to form on the coin, resulting in the chemical process of toning.
The way these layers are formed cause a captivating array of colours that collectors and enthusiasts admire so much. Colours can vary from delicate pastels to striking, vibrant rainbows.
Why do collectors look for toned coins?
While naturally toned coins are widely admired by many, artificially toned coins aren’t so coveted. Natural toning happens over many years as a result of the environment rather than the artificial method of accelerating the toning process using various chemical treatments in an attempt to enhance a coin’s appearance.
As a result, there are some coin collectors who will pay above and beyond the premium for colourful coins that are properly graded, while others won’t touch a toned coin. Those who don’t appreciate the natural toning process believe that the chemical changes affect and damage the surface of a coin, rather than enhance it. Others argue that coins with a vibrant history are reflected in the colouration that happens over time, and this is why collectors look for naturally toned coins, as their unusual colourations that hold a fascinating history are rare and unique to obtain.
The value of toned coins varies greatly, with the more vivid colours and variety of different hues attracting a greater value. Even coins that hold low monetary value or little significance can become rare collectables if they are naturally toned. Professional coin grading can help determine the value of these coins, giving you peace of mind that your coin’s toning is natural and authentic.
How to stop coins from toning
Since coin toning is a naturally occurring process, there’s not a lot that can be done to stop it from happening. However, the process can be slowed down if coins are kept in a dry environment with low-light exposure. It’s recommended that toned coins be left as they are, since trying to remove any toning can damage the coin’s surface and reduce its value significantly.
Instead, it’s worth embracing the natural and beautiful changes that have occurred over time, considering it as another part of the coin’s colourful and rich history.
The rarest toned coins
Now you know about the process of coin toning and how seemingly everyday coins can turn into rare and colourful collectables, you might be interested to learn about some of the most expensive toned coins discovered around the world.
- Rainbow Morgan Dollars – In 2022, an 1881-S Morgan Dollar had an initial guide price of $1,100 at auction, however, it was later realised at $19,387. At the same time, another Morgan Dollar had a similar listing of $250 but was sold at $8,812.50. Both of these coins were considered to be extremely rare and valuable due to the exquisite rainbow colourings as a result of hundreds of years of toning.
- Rare 1935-S Arkansas Half Dollar– This commemorative half dollar sold at auction for just less than $10,000 in 2022. Its coin toning was described as, ‘ranging from soft sky blue to deep coppery orange-gold and lemon yellow.’
- 1892 World’s Columbian Expo Half Dollar – The Proof 1892 Columbian half dollar was the third coin struck and sold for over $42,000. It features colourful rainbow toning and is considered extremely rare amongst numismatists and collectors alike.
- The Finest Toned Dollar in Existence – Another Morgan Dollar sold at auction for over $45,000 in 2014. It was described as ‘one of the finest toned dollars in existence,’ and featured, ‘rich vibrant branded rainbow toning over essentially flawless and highly lustrous surfaces.’
Many of the rarest and most coveted toned coins happen to be silver or copper, due to the way in which they tone over time. Don’t miss our guide to the rarest coins in the world to discover more of the most valuable and coveted coins by collectors.
How to care for toned coins
While coin toning can enhance the appeal of a coin, there’s a balance to be struck between preserving the toning and protecting the coin’s condition. Excessive cleaning or mishandling can disrupt the coin’s natural toned layers, and in turn, the value of the coin itself. This is why it’s recommended to leave toned coins as they are, respecting their age-old history and the kaleidoscope of colours they hold.
If you own coin jewellery, you also need to be mindful of how you care for it and keep it in the best condition possible. For advice, take a look at our tips on cleaning your coin necklaces, rings and bracelets.
Whether you’re a keen coin collector or simply intrigued by the beauty of toning, exploring the world of toned coins is a fascinating adventure. Each coin holds within it a story of chemical reactions, environmental influences, and an exciting history. So, the next time you come across a coin with a shimmering spectrum of colours, take a moment to appreciate its unique history and the journey it has been on to become a small, vibrant masterpiece.