The phrase “shipwreck coin” carries a certain mystique. It conjures images of buried treasure, sunken galleons, and ocean-crusted riches pulled from the deep. But what does that actually mean for a coin’s condition? This post strips away the romance and looks at the science. We’ll break down what shipwreck corrosion really is, how it affects…
Not all corrosion looks the same. Sometimes it’s a faint green haze creeping along the edges. Other times it’s a thick, black crust that seems to rise up out of the metal itself. Each color tells a different story, about what the coin has been through, what environment it’s been exposed to, and what kind…
Corrosion is one of the most destructive forms of damage a coin can suffer. It eats away at the surface, breaks down metal at a chemical level, and leaves behind pits, discoloration, or flaky crust that can make a coin nearly unrecognizable. Most of the time, corrosion happens when a coin is exposed to moisture,…
If you hang around coin collecting communities long enough, you’ll eventually run into a coin that looks almost too good. The shine seems unnatural. The details seem off. You flip it around in the light and feel like something’s not quite right. That’s usually when someone drops the dreaded comment: “It looks cleaned.” In this…
A details grade is assigned to a coin when a grading service determines that the coin has been altered or damaged in a way that disqualifies it from receiving a straight numerical grade. The grader still evaluates the coin’s level of wear (VF, AU, MS, etc.) but the final grade includes a note explaining the…
If you’re trying to spot cleaned coins, you’re going to run into a lot of confusing lines under the microscope. Not all of them are signs of damage. One of the most common points of confusion is the difference between hairline scratches from cleaning and die polish lines that are part of the original coin…
When a coin is polished, someone has taken it upon themselves to shine it, often with a cloth or something abrasive, to bring back that “fresh from the mint” look. Unlike whizzing, which uses high-speed tools, polishing tends to be more of a manual, low-speed process, but it’s still damaging. The results might look cleaner…
If a coin looks like it went through a belt sander, you’re probably looking at a whizzed coin. Whizzing is an aggressive and outdated attempt to make worn coins look “better” by mechanically buffing the surface, usually with a wire brush, Dremel tool, or polishing wheel. The goal is to create a fake shine, but…
Cartwheel luster — The radial light reflection seen on original mint-state coins, caused by microscopic flow lines from the minting process. Cleaned coin — A coin that has been altered after leaving the mint in an attempt to improve its appearance, often reducing its value. Details (grade) — A grade given to a coin that…
There’s something strange about a coin that’s technically “clean” but doesn’t look quite right. Maybe it shines just a little too much for its age, or maybe it seems unnaturally flat. That odd look might be the result of chemical dipping, one of the most common ways a coin gets damaged without a single scratch….