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Unintentional Ways Collectors Damage Coins – And How to Stop!

By Joshua McMorrow-Hernandez for CoinWeek …..
Most coin collectors know the major deadly sin regarding the handling of coins: don’t clean them! Yet a variety of coin-handling accidents will happen anyway. Many of the most well-meaning coin collectors have made some of the gravest mistakes when it comes to how they’ve handled, stored, or otherwise managed their coin collections. It’s simply too easy to damage coins beyond repair – the slightest of surface friction, an errant slip of the finger, or even buying an outdated coin holder can spell figurative and literal doom for coins.

There are a million-and-one ways that coins have been permanently damaged in the otherwise caring hands of the collectors who love them. So, what are some of the more common ways collectors have unintentionally ruined their coins, and how can you prevent such fates from happening to you and your prized numismatic possessions? Here’s a look at some of the most frequent offenses and how to stop them from happening to you!

Can’t Return To Sender…

Boxcutters can scratch coins causing damage

Is there a more heartbreaking way to damage a new arrival to your collection than by accidentally cutting it with an X-Acto knife or another sharp object as you open the mailer in which it was shipped? It’s happened to so many collectors and dealers that it’s easily one of the top ways numismatists mishandle their coins.

Most often, the coins are shipped safely and well but are layered in bubble wrap, bound in tape, or otherwise covered in tightly wrapped, well-sealed packaging that necessitates the use of a knife or blade to open. Take extra care when opening these packages and remove each layer as if performing meticulous surgery on the item. Yes, we know you’re in a hurry (aren’t we all?). Yes, we know you’re anxious to see what your new purchase looks like. But take the time to open your packages carefully… Remember, any damage that happens to your purchase after it arrives is not eligible for a refund!

2x2s of Doom

Peace Dollar - Staples damage coins

2x2s are ubiquitous. Probably the only supply item more numerous in coin collecting than 2×2 cardboard holders or similar mounts are the staples used to secure them. And while the staples are an important part of keeping your coins secured inside, there are a few inherent risks involved in sealing a coin within or removing a coin from a 2×2.

The first dangerous part comes in stapling the holder together. Don’t position the stapler too close to the coin, lest you ding it with the head of the stapler; rather, staple the holder as close to its edges as possible. One errant move with a stapler placed too close to a coin and your pristine piece could be damaged goods. But that’s not the only numismatically risky part of working with a 2×2. Oh, good heavens no…

Ever tried using pliers to crimp the bubbly loops on the business end of a staple against the flat panel of the 2×2? Not only does crimping the staple loops help save space in row boxes, but it also helps prevent scratching of the staple ends against other coins, and crimped staples are the mark of polish and professionalism.

But be careful how close those pliers get to the coin. You don’t want to put big ol’ cuts into the rim!

And taking coins out of 2x2s can seem innocuous enough of an act that some of us let our guards down, but there’s a lot that can go wrong when taking coins out of stapled cardboard holders. The coin could get scratched by a staple. You might accidentally put your greasy fingers on the coin’s surface. The coin might drop out of the holder and get damaged upon impact with a hard surface such as a table or floor.

In other words, 2x2s lend a plethora of risks that could easily and irreparably damage coins. Nevertheless, there are ways to help mitigate these risks. In addition to the precautions listed above, you might consider the following to safely remove coins from 2x2s:

  • Wear cotton gloves to avoid direct contact with the coin surfaces.
  • When removing coins from 2x2s, do so over a soft, padded surface.
  • If you can practically do so without imparting more damage to the coin inside the holder, remove the staples with a staple remover – but be very careful not to scrape the coins inside the holders.
  • If you can’t safely extricate the staples from the holder before removing the coin, then carefully pry the holder open and be sure the coin within does not come in contact with any part of the staples – or fall out onto a hard surface.

While 2x2s aren’t considered ideal for long-term storage, they do represent a good combination of decent short-term storage safety and overall economy. Thus, 2x2s will likely remain an important part of our hobby for the foreseeable future.

However, an excellent way you can remove the risks commonly associated with conventional 2x2s is to buy self-sealing 2x2s both for selling your coins or storing the ones you have in your collection. Self-sealing 2x2s are a little more expensive but they can save money on staples, the time required to work with 2x2s, and they can also eliminate the staple-related risks that come with later removing coins from the holder.

Slimy PVC Holders

There was a time in our hobby during the 1960s, ’70s, and even into the ‘80s, when polyvinyl chloride–more notoriously known in numismatic circles as PVC–was considered a beneficial product. This popular polymer helps make plastics more pliable and less brittle, and it was once found in everything from coin albums to display cases.

But time hasn’t been kind to PVC’s standing in our hobby – and it certainly hasn’t been nice to the coins once contained within PVC-riddled holders.

Slime from PVC can ruin a coin's beauty and cause damage to its surfaceThe reaction between PVC and coin metals (especially coins stored in hot, humid conditions) has left many coins with pernicious and permanent PVC damage. And not only does PVC damage the coins it has directly come into contact with, but, even more scarily, the PVC damage can also spread to other coins in a collection, much like an infectious disease.

Acidic PVC damage manifests in many corrosive forms. The most common and widely known sign of PVC damage is a green film that forms on coins – though it may also be seen in blues, greys, yellows, and other colors, as well as in streaks or splotches across some or all of the coin’s surface. Porosity and other forms of corrosion may be seen as localized or widespread pitting.

While PVC damage is generally irreversible, there are ways to prevent further damage to coins already afflicted by this synthetic scourge.

One of the most common methods is to bathe the coin in acetone for at least 30 seconds to remove the PVC goo, a process most safely done while wearing gloves and working in a well-ventilated area.

You could also submit the coins for professional conservation, though many such services have certain restrictions and special contractual clauses concerning the treatment of PVC-damaged coins.

So how do you avoid subjecting your coins to PVC altogether? Quite simply, keep them away from coin supplies that may contain PVC. Be wary about placing them in older holders, especially those with plasticized elements such as slides or covers. The softer the plastic, the more likely it contains PVC, so be sure to avoid using unvetted soft plastic flips or any albums that contain (especially pliable) plastic components.

It’s best to play it safe and buy modern coin supplies that are marked as “inert” or otherwise PVC free. If you suspect any of your coins are presently in albums or other display products that may contain PVC, be sure to remove them as soon as possible and place them in inert holders. It may not be a bad idea to have the coins professionally treated for PVC exposure, as well.

Preventing Environmental Damage


Coin metal is finicky. While gold is fairly stoic when it comes to responding to the environment around it, silver and especially copper are highly reactive metals. Copper in particular is prone to corrosion and a host of other problems. And like a canary in the coal mine, copper coins will often be the first in one’s collection to exhibit naked-eye visible responses to problematic environmental issues such as heat, humidity, and fumes.

Many collectors are prudently cautious about how they store their copper coins, and some dealers who attend coin shows in various regions of the United States or other parts of the world won’t travel with them during hot summertime weather. Some altogether avoid going to places like Florida, where the air mass is generally humid and, particularly near the state’s hundreds of miles of shoreline, is also somewhat salty.

Humidity can result in problems for copper coins

Regardless of what types of coins you collect, you need to be careful about how you store and handle them. It’s best to keep them in a cool, dry environment away from direct sunlight, sources of heat, and any fumes. Don’t store your coins in places with excessive humidity, namely any non-climate-controlled areas of your home, such as a basement, attic, or garage. If storing your coins in a bank safety deposit box or other off-site location, make sure you know what the climate settings are like, and don’t assume they’re necessarily within safe parameters for coins storage. If necessary, add silica gel packets to your vault or other storage containers to wick away moisture and help stabilize humidity levels.

Store your coins in holders that don’t allow for the passage of air or the entry of moisture and impurities. Modern coin slabs from the major reputable third-party coin grading firms represent some of the very best coin-storage technology around today.

But if you can’t have all of your coins encapsulated, then the next best bet is to seek coin albums and display cases that provide similar protection (of course, per the previous point, avoid buying supplies that may contain PVC!). Inert flips are OK for storing your coins though perhaps not quite as ideal as containers and organizational supplies that seal the coins off from air and moisture entirely.

Don’t store your coins in paper envelopes, which not only permit the free flow of air and moisture but also contain sulfur – an element known to damage coins over time. And although coin folders are popular for organizing coin collections, this method of storage is not chemically ideal for the coins themselves, as the sulfur within the cardboard and glues used in the folders may damage your coins in the long run. What’s more, coin folders, coin envelopes, and similar methods of storage can also impart friction on the high points of a coin – something that is irreversible and could actually decrease a coin’s wear-based grade.

High-point friction is in part why the use of coin cabinets fell out of favor during the early to mid-20th century. Though a most ornate and ostensibly luxurious method of coin storage, coin cabinets pose several numismatic storage problems, including the cabinet friction imparted on coins as they slide in and out of drawers, exposure to air and moisture, and the risk of fingerprints in lifting the coins out of their drawer trays and placing them back inside.

Don’t Leave Fingerprints

Sometimes we leave our tracks behind on coins, and this is most commonly done by way of fingerprints.

Fingerprints on an American Silver Eagle

It’s not difficult to impart these unsightly and often permanent memorials to our stewardship of the coins we have in our collections. One misplaced finger on the obverse or reverse of a coin and we may be reminded of this mistake months or years down the line when a fingerprint shows up in that spot. This is especially true with Uncirculated and Proof coins, as well as copper coinage in general. Though in theory, a visible fingerprint could show up on any coin regardless of its grade or metallic composition.

Thankfully, it’s easy to avoid leaving fingerprints behind on coins. These distracting and often grade-impairing imperfections are typically seen on coins that have been handled by dirty or greasy fingers and stored in hot, humid locations. Wearing gloves and properly holding a coin by its edge with your thumb and forefinger virtually eliminates any chance of leaving fingerprints behind – though gloves may increase the chances of dropping your coin.

You can further mitigate these risks by washing your hands prior to touching any of your coins to remove grease, dirt, and other foreign matter beforehand.

Don’t Be Taken to the Cleaners

It’s pretty much impossible to overstate the immediate and long-term problems that come with cleaning coins. Not only does cleaning a coin potentially remove a thin layer of its metal from the surface, but it also artificially alters a coin’s appearance by removing the natural patina it has accrued over a period of years. Stripping away a coin’s outer layer leaves many immediate and undesirable post-cleaning effects. The long-term effects can be even worse…

Sometimes coins re-tone unevenly after cleaning, leaving splotchy or streaky coloration or toning on affected pieces. Often the colors the coin acquires don’t appear natural. And, besides, a skilled numismatist will be able to tell a coin was cleaned even many years after its re-toning process has begun. This is especially the case with harsh cleanings involving caustic chemicals and abrasives. Cleaned circulated coins often have an unnatural but flat shine, higher-grade pieces may have dull surfaces, and pieces that once showed plenty of gorgeous mint luster will lose their beautiful bloom.

Of course, not all cleanings are undertaken with the intent of defrauding a collector. Certainly, there are many innocuous reasons why a collector may attempt to clean a coin. A well-meaning coin collector simply may be trying to remove old adhesive left behind from someone who once taped the coin to the inside of a folder or a display. Or maybe a collector wants to remove a greasy clump of residue sitting in the crevices of the coin’s design or lettering.

In virtually every case, what ends up happening is the cleaning leaves more negative results than it does positive ones. It’s never a good idea to clean a coin – at least not in the conventional ways most collectors hear about. You’ll find 1,001 online articles, YouTube videos, and other posts describing all manner of ways to clean copper coins with vinegar and baking soda, remove “tarnish” from silver coins using toothpaste and jeweler’s rubs, or otherwise make old coins look “new” again. And more recently there have been a rise in the number of posts suggesting the use of acidic tomato-based ketchups and salsas for lightening copper coins.

However, vinegar, baking soda, and condiments add up to nothing more than a recipe for numismatic disaster. These are all highly damaging and extremely amateurish approaches to the matter at hand. If tepid running water isn’t sufficient for sloughing off loose dirt or debris on your coins, and acetone won’t do the trick in knocking out adhesives, glues, or other unwelcome surface guests, then submit your coin to a professional conservation service. The professionals know what coins can – or cannot – be properly conserved and will employ best-practice techniques for safely conserving your coins or saving them from further ruin.

Being the Best Coin Collector You Can Be

If you’ve committed any or even all of the coin handling mistakes listed in this article, take heart – everybody makes mistakes. Many of these unintentional errors are worse than others. But sometimes it’s only through trial and error that we learn what not to do in life. And through our mistakes we can become better numismatists.

So, if you’ve accidentally scratched a coin while removing it from a mailer or a 2×2, placed coins in PVC-riddled holders, or left behind a biomarker or two on some of your coins – why, even if you’ve scrubbed your old silver dollars with the harshest combination of toothpaste and baking soda known to mankind – laugh and learn from your mistake, then move on. What’s done is done. You’ve gained invaluable wisdom in the process and surely you now know what to do differently to avoid making the same mistake again. It’s all part of the enriching learning experience in this great hobby we call numismatics.



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    • Taylor: Except for the rather presumptuous comment you wrote, nobody knows who you are, or what coins you have….. so how could anyone be judging you? Might want to knock that chip off your shoulder and listen a bit more. Trust me, nobody cares what you do with your coins. Merry Christmas!

    • When you go to sell any coins, any damage will be apparent. It is best to care for your treasure, so that it will stay in the best shape.

  1. Amazing how the most simple thing as collecting can be so confusing to so many. After being a collector for over 40 years and past President of 2 coin clubs; I’ve found that most people appreciate knowledge and make more of an effort to do the right thing once they are given a chance. You’ll always have the few that will continue to destroy their collections and ones that hope it will get better. Some try to collect so they make a few dollars when they try to sell. Then again you have the Stewards that try to persevere for the future. Either way only the individual can make the decisions on which way to collect. I highly recommend talking to others and possibly joining a coin club if it’s available. Coin collecting can be fun and full of history.


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