2004 Canada Dime. Can anyone explain this?

YQQ

Hopefully, someone can explain what caused this dime to be like this.
It appears the copper plating is there but the nickel plating is missing?
it does not look like it has peeled off. it is not there on both sides.
For me, it is a mystery.
thanks, everyone for your input.

Sapyx

Teh plating was originally there, and is still there, around the rim. You can see where it is flaking off. From the looks of it, it appears that someone has meticulously and laboriously hand-picked the plating away from this coin.

The coin certainly didn't leave the Mint looking like that. And I can't see this sort of thin happening by accident. Someone deliberately damaged the coin, to make it look like this.

Why? You'll have to find them and ask them.

amwldcoin

Wonder if a washing machine would do that? I'm sure an old timey 1 probably would.

JWP

Looks like environmental damage and or extreme cleaning.

YQQ

Thanks guys,
but this coin has never been cleaned in any way.
but this coin has never been cleaned in any way.
This is also not corrosion or other env damage.each of your above suggestions would have left its own very clear identifying evidence. IMO, it is also not PMD.

syl

It most definitely did not leave the mint like that.

Sapyx

Canadian coin blanks are made by a multi-ply plating process; alternating layers of copper and nickel around a steel core.

What we're seeing here is a coin where the layers of nickel, plus the layers of copper, have peeled away from the surface of the coin - only the obverse and reverse surfaces, and not the rims - showing the underlying treated steel surface (the grey layer) plus the actual rusted-steel core (the brown layer).

This peeling away did not happen before the coin was struck. If it had happened before it was struck, then (a) there would be a lot more detail showing on the coin (it wouldn't be all blurry and fuzzy), and (b) the boundary where the remnant of the outer plating layer ends, would have been smashed flat down onto the surface of the coin. So whatever happened, happened after the coin was struck. Which in turn means it was post-mint damage, and not a mint error.

I also notice that the details on the parts of the coin where the original plating have survived - specifically, the denticles around the rim - are very ill-defined, as if worn. So my new theory on how this post-mint damage might have taken place, is in a rock tumbler or some similar jewellery-polishing device. Here's my guess: someone found this coin metal-detecting, and it looked a corroded mess, so they tossed it into the rock tumbler with a bunch of walnut shells or steel pellets or whatever they chose to use, to try to clean it up. But the coin had pinhole damage to the plating across both surfaces, creating a corrosion bubble underneath the plating. The tumbler smashed away the bubble surface and cleaned off the corrosion that was underneath, but wasn't strong enough to remove the plating where it was still strongly bonded to the coin, around the rim.

PBRat

The dime looks like it had a small pool of an acid solution placed on one surface, possibly sulfuric acid or nitric acid. This ate into the nickel plating, which could be flaked off, exposing the steel core.

Then, repeat on the other side.

Next time I am playing chemistry, I may try to replicate this effect.

Sapyx

I wouldn't have thought it would be acid, simply because any acid strong enough to eat through pure nickel ought to eat straight through the steel core and turn it into mush.

PBRat

That's why I said I wanted to try to replicate. It would be all about the acid strength, timing, and type of acid. You'd just need to corrode the nickel plating enough so it could be flaked off, but not penetrate to the steel core. And, maybe sulfuric acid would react with the core to produce a protective layer of ferrous sulfate.

Sapyx

I don't think that will happen with sulfuric, unless Canada uses a much more "stainless" steel in their coin cores than I'd anticipate. For mild steel, you might get a passivation layer with phosphoric acid, but I don't think phosphoric would react with the nickel at all.

I still think it'd be far easier to replicate this damage with physical, rather than chemical, attack.