Environmental damage happens when copper reacts with oxygen, moisture, and soil chemicals. This 1881 Indian Head Cent shows every stage of that breakdown, from green corrosion to missing metal. It is not a mint error, but it is a perfect example of how copper changes over time.
A shiny coin isn’t always a good coin. Real value comes from originality, not polish. Once a surface is stripped or buffed, the damage can’t be undone, no matter how good it looks in photos.
Everyone hears “never clean your coins,” and it’s usually the right advice. But there are a few rare situations where it actually makes sense. Here’s when to consider it and how to do it without ruining the coin.
If you just found a coin with green crust on it and you’re wondering if it’s dangerous, you’re not alone. That green stuff is called verdigris, and it shows up on a lot of older pennies and copper coins. The short answer: it’s not deadly, but you shouldn’t eat it. Verdigris can be mildly toxic…
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…
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…
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?…
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…
Verdigris isn’t just a problem for the coin it appears on — it’s contagious. If you’ve got a coin with active green corrosion sitting in a flip, tube, or roll, it could be slowly eating away at everything it touches. In our last post, we broke down what verdigris is and how to spot it….
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…