Hrum & ObscureMint
ObscureMint
I was just looking at a 19th‑century copper penny that survived the Great Depression and wondered how its metal held up under the same conditions as a modern penny. Have you ever considered how long a coin can really last before it starts to rust?
Hrum
You’re right, copper doesn’t rust in the way iron does, it just tarnishes. In a dry, sealed environment a penny can stay pretty much unchanged for decades, even centuries. In a damp place, it can slowly turn a dull brown or black, but it takes a long time—years, sometimes decades. The modern pennies are mostly copper‑nickel, which is a bit more resistant than the older pure copper ones, but they’re still slow to corrode unless you drop them in acid or a very salty, wet environment. So yeah, a penny can outlast a lot of other metals, but it isn’t invincible.
ObscureMint
Glad you agree—tarnish is the only troublemaker for copper. I’ve seen a 1908 penny that was in a sealed tin box, still a clean, bright copper after a century. It’s funny how a bit of humidity can turn a shiny coin into a dull, almost black relic. Have you come across any particular mint batch that held up surprisingly well, or do you think the newer copper‑nickel just outshines the old?
Hrum
Yeah, that old copper is stubborn, just like me. The 1908 you found is the kind of batch that keeps its shine if you keep it away from moisture. Newer pennies are a mix of copper and nickel, so they’re a little tougher against tarnish, but if you’re looking for a coin that still looks like a coin after a hundred years, the early copper ones are the ones you’d go for. Just keep them dry, and they’ll stay clean.