Due to their very nature, Precious Metals are prone to not only damage, like nicks and scratches, but also toning and tarnishing. Acquiring the Precious Metals you desire for your collection, be they bullion or pristine collector pieces, is just the first step to building a collection of your own. The next is to take steps to protect and retain the value of that collection.
What Causes a Coin to Tarnish?
Coin damage is something every collector aims to avoid. Toning is a natural part of the aging process for coins. However, the amount of toning or tarnishing that a coin develops can be limited by adhering to proper storage practices. Some toning on silver is black and detracts from the coin’s eye appeal, but sometimes attractive colors and hues develop instead.
Tarnishing is primarily caused when the precious metal silver is exposed to oxygen and the various chemical compounds in it, and a reaction occurs. Environmental factors like humidity and exposure to oxygen, in general, can lead to tarnishing which often results in a “dirty” looking coin that is actually a film that appears on the surface of the coin. Toning occurs under slightly different circumstances but occurs from silver reacting to various chemicals. For example, black toning results from the interaction of sulfides in dirt and silver.
Gold itself is not terribly prone to tarnishing since it is an inert or chemically complete metal, however, because it is often alloyed with other metals due to its soft nature, those other medals can cause spotting or toning. Copper is primarily used as an alloy with gold, and copper is prone to oxidation, or rust, so reddish “copper spots” can occur on gold coins when exposed to the outside elements.
How to Prevent Coins from Tarnishing and Toning
If you want to prevent silver coins from tarnishing or toning, then they need to be kept in a dry controlled climate with limited light exposure. The less exposed to air and outside elements, the better. Many collectors chose to use plastic capsules that not only minimize exposure to the elements, but that add an extra layer of protection from dings and nicks. While this will not stop toning 100%, it may slow it down.
Location is key. When storing your coins, it is imperative that you choose a place with as low humidity as possible and that is temperature-controlled. While high or low temperature in itself may not harm coins, the transition between the two, and the resulting condensation, can lead to toning and even oxidation. You would not want to store your coins in a garage or a laundry room for example.
For those who prefer to store their uncertified coins in square flips, be wary of the material they are made out of. Some of the chemical compounds they are made out of can adversely interact with the precious metals in coins. Be on the lookout for PVC or polyvinyl chloride, as this plastic, in particular, will react with coins and lead to the formation of green discoloration.
How to Identify Dipped and Artificially Toned Coins
Dipped coins and artificially toned coins are not appealing to many collectors because they are essentially damaged. These are among the most frequently encountered types of coin damage. Coins that have been dipped were exposed to an acidic cleaning solution. Use of coin dip can result in some immediate results, but overall it is detrimental and causes acid damage. In some cases, it even accelerates oxidation and undesirable toning. It’s not unheard of for a silver coin to begin showing black tarnish or toning after being dipped.
Identifying a dipped coin is possible, although it can take a while to become familiar with the appearance of these specimens. Coins that have been dipped lose their original Mint luster. When you tilt the coin around, it will not reflect light like an uncirculated specimen that hasn’t been dipped. Dipped coins have surface damage from their exposure to acids.
Artificially toned coins are more obvious in many cases. For example, you may see modern silver bullion coins with very overt and bright toning even though they are only a few years old. These are artificially toned specimens.
Mistakes People Make When Storing a Coin Collection
While coin storage is rather simple, it is critical if you want to avoid coin damage over the years. It’s easy to look at pocket change and see coins that have been damaged in machines or foreign substances, but there are a number of things that can go wrong when coins are in storage for long periods of time if the conditions are off.
First of all, it is imperative to store your coin collection in a place with a stable environment. If you’re looking for the best way to store a coin collection, start with somewhere that has low humidity and protection from light. Light, humidity, and temperature can all have detrimental effects on coins over time.
Once you have chosen a suitable area, then you just need to make sure you have the right coin-collecting supplies. Whether that means coin albums, coin capsules, tubes, or something else is up to you and your circumstances.
Over the decades, many collectors have simply left their prized coins tucked away in a corner in boxes. Some were exposed to light, while others were exposed to moisture or even adhesive from tape. All of these can create undesirable qualities in a coin and the damage can’t be undone without professional help if it can be undone at all.
To learn more about common coin collecting mistakes, read this Info-Vault article titled “Top 5 Biggest Coin Collecting Mistakes and How to Avoid Them.”