Double Edged 1 Euro Cent! Is It Valuable?

If I get what you're referencing to is the raised area inside, not just the thickness of the rim...then that raised portion I see is caused by a worn die. As dies "age" through use, metal flows on the die outwards forming ridges like that. Letters and other details stretch and move closer to the edge too. See that on T of cent and lines wrapping up.

Another far fetched possibility if the coin is slightly larger in circumference is an incomplete color or out of collar strike, ONLY f coin is larger tho...

And even another which upon further gazing may just be it is a soft strike, didn't compress the coin enough to expand detail against back pressure of collar. That would explain the thick rim and 2nd ring. Hard to tell w/o coin in hand

Roberto, do think it is a mint strike error, would suggest saving it and verifying w/ reputable dealer.

Robertp,, sorry, not the normal wear of coin circulation. The making of coins, the die has the coins details that impress it in a coin press. That wears out after continued pressure of minting. That metal piece called "die" is what "expands". I do think its an error of striking the coin, but exactly what and how it happened I'm not sure. I have never seen a blank Euro "planchet" the unstamped coin. I don't know how much rim is formed on those blanks, that makes a difference too.

This is simple diagram of a die press:


Our US Planchets look like this, a slightly raised edge



Here's a few examples of extreme die wear and what effects are seen:





Yhat's why I think your coin is a weakly struck coin more than just a result of a worn die.

Oh I just saw the picture. Maybe the planchet was a bit bigger.