Because we are a Grand Rapids coin dealer, local clients often ask us what affects coin valuation. Condition of a coin is particularly important--condition is often affected by how a coin is stored over long periods of time. If you’re new to collecting coins, be careful how you care for your collection. To protect your investment, and to maintain the appearance of your collection, we recommend some basic practices for handling, cleaning, and long-term storage.
Part of the enjoyment of collecting coins is the ability to examine them. Therefore, to preserve the value and condition of your collection, careful handling is crucial. And for uncirculated or proof coins, you may even want to leave them in their holders and not handle them at all.
For the coins you do handle, it’s always best to wash your hands before handling them. This minimizes transferring oils, sweat, food, and plain old bacteria to the coins, which can cause corrosion or discoloring, thereby downgrading your coin’s value. Many collectors even use special white cotton gloves to handle their collection, especially when handling uncirculated or proof coins.
Even if you leave coins in a holder when handling them, bear in mind that even sonically sealed holders can crack open when dropped. Therefore, whether your coins are in holders or not, it’s a good idea to handle them over a clean, soft cotton cloth or felt paper, which will also give you a place to set them. Also, make sure that the table is clean, and that you don’t eat or drink while handling coins. You should even be careful not to talk directly over the coins, because tiny saliva droplets can end up as spots on the coin’s surface, which can affect the value of your coin collection. Finally, when holding a coin, hold it by the edge between the thumb and forefinger to protect the obverse and reverse sides from fingerprint smudges and scratches.
Generally speaking, cleaning a coin tends to alter its surface and drastically reduce its value. Experienced collectors and dealers can spot a cleaned coin with a mere glance, and rarely give them a second look.
Unless a coin has PVC damage (residue from soft plastic holders that leaves a green goo after a long period of time) or the surfaces are covered with grease and dirt, coins should not be cleaned. When cleaning is necessary, it is because the coin has little value in its current state. In almost all cases, uncirculated coins should not be cleaned. However, if you have a coin which must be cleaned and you want to remove existing oils, PVC or dirt from the surface to prevent further damage, here are a few tips.
Do not use cleaning products with abrasive chemicals. Do not use products which will change the coin’s color. Do not wipe or polish coins... doing so will leave “hairlines” which devalue the coin.
Do use washes intended for removing dirt and PVC from coins. Do wash one coin at a time per directions of the cleaning solution. Do wash your hands in advance of cleaning. Do rinse coins with distilled water. Do allow coins to air dry or use a compressed air canister. Do make certain coins are dry before storing.
When you choose containers for your coin collection, choose carefully, because even chemicals in the storage containers can damage or discolor coins. The main options for storing your coins are:
· Envelopes: inexpensive, individual envelopes. The envelopes themselves are acid-free, and should only be labeled with photo-safe or acid-free ink.
· Flips: PVC-free plastic bags that are a bit more expensive than envelopes. Flips allow you to view a coin without removing it from its container.
· Holders: Mint-issued holders that are designed specifically for coin storage. This packaging is often part of a collectible set, so if you keep the set in the packaging, it helps maintain the set’s value.
· Slabs: hard plastic packages for individual coins. A slab, which normally also displays the coin’s grading information, protects the coin without obstructing the view of the coin. Coins are usually slabbed by coin dealers or grading services. Special boxes with grooves for the slabs can be used to store a large number of slabbed coins, and some coin display boxes are designed to accommodate the coins in slabs as well.
These containers are easily ordered online from coin supply companies.
Many collectors take special pride in caring for their collections, and may develop practices even beyond our basic recommendations. If you have thoughts about handling coins, or lessons based on experience, please register your comments below. And if you have questions about caring for your collection to preserve coin values, contact us at Mullen Coins, 616-272-4402.