After rarity, condition is the main thing that defines a coin’s value. The good news: you do not need expensive equipment to preserve a coin. A few habits and the right materials are enough.
Three enemies of a coin
Touch. Sweat and skin oils leave fingerprints that etch into the metal over time. They show most on the mirror fields of silver coins. Hold a coin by its edge only, ideally wearing cotton or nitrile gloves.
Moisture and temperature swings. Both speed up oxidation. Keep your collection in a living room, not on a balcony, in a basement or next to a radiator. Put a sachet of silica gel in the box or safe and replace it from time to time.
Poor materials. Soft PVC plastic releases compounds over the years that leave a greenish sticky film on the coin. The same goes for random envelopes, rubber bands and adhesive tape.
What to store coins in
- Capsules. The best protection for a single coin. The capsule diameter must match the coin: in an oversized one the coin slides and rubs.
- Holders. Cardboard frames with a clear window. Cheap and handy for inexpensive coins, but staple them so that the staples do not touch the coin.
- Albums and trays. Good for seeing a whole series at once. Choose PVC-free pages, usually marked “PVC free”.
- Original packaging. Modern NBU commemorative coins are sold in capsules or souvenir packaging. Do not take the coin out unless you need to.
Five beginner mistakes
- Cleaning. The most expensive mistake. Paste, baking soda or silver polish remove the top layer of metal and leave micro-scratches. A cleaned coin is almost always worth less than a toned one.
- Coins in one pile. They scratch each other. Every coin should lie separately.
- Throwing away the packaging. The capsule, certificate and box are part of the set. Without them a coin is harder to sell at full price.
- Fighting toning. Even darkening of silver is a natural process, and many collectors value it. It is not a defect.
- Keeping no records. A few years on, it is hard to recall what you bought, when and for how much. Write it down straight away.
Keep track of your collection
Your Coin Treasure account has a “My collection” section: add coins with their purchase price and date, and you will see how the value of your collection changes.
If you are looking for something to add, browse the commemorative coins catalogue.
