Storage & Handling

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Should You Use Acetone on Coins?

Acetone gets thrown around a lot in coin forums. Sometimes as a miracle fix, sometimes as a dangerous tool for people who don’t know what they’re doing. The truth is somewhere in the middle. Acetone is a solvent that can safely remove certain types of surface contaminants without damaging the metal underneath, if it’s used…

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Is Tarnish Bad? How It Affects Value and Eye Appeal

Tarnish is the thin layer of surface discoloration that forms on a coin when it reacts with elements in the environment like oxygen, sulfur, or moisture. It’s not deep corrosion, and it doesn’t usually eat into the metal. Instead, tarnish sits on the surface and changes the coin’s color. Sometimes slightly, sometimes dramatically. It’s most…

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Tarnish vs. Toning: What’s the Difference?

In the world of coin collecting, the line between “tarnish” and “toning” is surprisingly thin, and often debated. Both are surface changes caused by chemical reactions, usually with sulfur or oxygen, but one is often seen as damage while the other might add hundreds (or thousands) of dollars in value. So what’s the real difference?…

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What Is Tarnish? Understanding Natural Surface Changes in Coins

Not all discoloration on a coin is bad, but it’s not all good either. Tarnish is one of the most common surface changes collectors encounter, especially on silver coins. It’s the dull film that creeps across a coin’s surface over time, shifting its luster and tone without necessarily damaging the metal itself. This post is…

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Verdigris: What It Is and Why It Shows Up on Coins

Verdigris is that weird green stuff you sometimes see on old copper or bronze coins. It can range from a faint, minty haze to thick, crusty blobs that look like the coin was stored in a compost pile. And while it might look kind of cool in certain lighting, it’s not a sign of anything…

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What Counts as Environmental Damage?

If you’ve ever submitted a coin for grading and gotten the dreaded Environmental Damage tag back from PCGS, you know how frustrating it can be. Unlike more specific designations like “Cleaned” or “Scratched,” this one feels like a catch-all, but there’s a little more to it than that. This post breaks down exactly what PCGS…