Handling and Storing Bullion Coins: Capsules, Tubes and Milk Spots

Bullion coins are bought for their metal, but their condition still matters. A scratched or stained coin contains the same amount of gold or silver as a pristine one, yet it may fetch less when sold, especially if it has any collector appeal. Good handling and sensible storage cost very little and help keep coins in the state in which they were bought.

Handling: the basic rules

Skin carries oils, moisture and salts that can mark metal surfaces, particularly silver and pure 24-karat gold.

• Hold coins by the edge, between thumb and finger, never by the faces.
• Wear gloves when handling coins out of their packaging. Cotton or nitrile gloves are common choices.
• Work over a soft surface, such as a cloth or a padded mat, in case a coin is dropped.
• Do not breathe or talk directly over coins, since droplets can leave spots.
• Never clean a coin. Polishing, dipping or rubbing leaves fine scratches and changes the surface, which reduces value for collectors and can look suspicious to dealers.

Pure gold coins such as the Canadian Gold Maple Leaf or the American Gold Buffalo are softer than 22-karat coins and mark more easily.

Holders: what to use

Holders: what to avoid

Avoid soft plastic flips and albums made with PVC (polyvinyl chloride). Over time, PVC releases chemicals that can leave a green, sticky residue on coins, causing permanent damage. Materials described as PVC-free, such as those made with polyethylene or polypropylene, or archival-quality holders, are safer choices. Paper envelopes containing sulphur can also tarnish silver.

Milk spots on silver coins

Many owners of modern silver bullion coins have noticed white, cloudy marks on the surface, commonly called milk spots. They appear on coins from several mints, sometimes months or years after striking, and even on coins that have never been touched.

• They are thought to be linked to residues from the minting and washing process, rather than to anything the owner did.
• They do not reduce the silver content and are irrelevant for melt value.
• They can reduce appeal to collectors and sometimes slightly affect resale to buyers who care about appearance.

Some mints have introduced changes in their processes intended to reduce the problem. There is no reliable way for an owner to remove milk spots without risking damage, so prevention, through good storage, is the only practical option.

Environment

The storage environment matters more than many owners expect:

• Humidity speeds up tarnishing. A dry place, possibly with silica gel desiccant packs that are replaced or regenerated regularly, helps.
• Temperature swings can cause condensation inside holders.
• Air pollutants, especially sulphur compounds found in some rubber, wool, paints and household products, tarnish silver.
• Light has little effect on metal itself but can degrade some plastic holders over time.

Where to keep coins

Physical location is a separate question from handling. Options include a home safe, a bank safe deposit box or a professional vault. Each involves trade-offs in cost, access, insurance and security. Whatever the choice, keep an inventory with photos and purchase records, stored separately from the coins, and check what your insurance actually covers, since many home policies cap cover for precious metals.

A simple routine

1. Buy coins in, or move them into, suitable inert holders.
2. Handle them only with gloves and only when necessary.
3. Store them dry, stable and away from rubber, wool and PVC.
4. Keep paperwork and an inventory.

These habits protect value at almost no cost. For related advice, see our guides to buying silver coins, silver coin values and selling bullion coins.

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