What's wrong with euro coins?

Hello all

As lots here, I collect euro coins so I guess the topic would be of interest.
I store 2 euro coins in plastic capsules and I have some mint blisters as well. Coins in the mint blisters have never been removed, I let them here.
Recently I found out that on some coins in blisters have appeared some small, ugly black spots. The others were instead flawless as they were when I bought them. The damaged coins were 1, 2, 5 and 20 eurocents from 4 different blisters. 20 eurocents, Spanish folder, has a white spot.
Some 2 euros,encapsulated,show some little black dots (these are different, they look more like microscopic dirt). And one of these was bought directly from the mint, I bought it personally on a visit.
Now: I don't open or close the capsules (which are of a famous German brand, starting with L) and the blisters were stored all together in a part of the house that I thought it was dry (although humidity is very high where I live).

Now.. The problem seems not so uncommon, basing on what I saw on net. One on net bought a Monaco 2001 unc series in the official blister, and after a few years all the coins had big black spots... Just imagine the waste of money.

Still, no one has a clear answer to that. Someone says some mint blisters have low quality and in the long term let the air passing through. Some others say it is the metal used for euro coins that sometimes is so low quality it reacts to everything.
All I know is that I saw this problem just with euro coins, so I wanted to share.
Suggestions and explanations are welcome!

It has not much to do with "low" quality, not that I want to say that these as cheap as possibly made coins are the pinnacle of human engineering. It can either be, or most likely is a combination of impurities that are really not avoidable in mass production of that scale, the humidity and oxygen of the air and temperature highs and lows. For some reactions it is enough to be exposed only a short period of time to the right conditions and over a long time will react further even with little additional exposure.
Similar to the milk-spots on bullion coins minted on insufficiently washed blanks. What was once a nice shiny round that you put in an air tight container will turn opaque spotted without anything you can do about it.

In other words there is no way one can be sure that the coins will not show spots or be damaged over time, no matter how and where they are stored.
Personally I think there is still much to know in this field. Take the silver coins, that you mentioned.
Everyone agrees on no PVC plastic sheets, PVC will react with the silver and damage the coin, sooner or later. But that's all we are sure about.
Some store it in no pvc hard plastic, some don't cause they THINK the plastic could react in the long run. So they go for velvet, but not the synthetic one, as that is bad. Fine, but you have to turn the coin once in a while so that it gets uniform patina on both sides. Some others go for plastic capsules, but still you can't be sure something bad will happen.

I personally tend to leave coins in their original folders and put them in a stable environment. But as a collector, I know that there are no zero risks in any case and gotta keep that in mind.

I would guess that OP is not properly storing the coins.

Put them in an airtight ziplock, and another one. Then store them in an airtight box away from the sun and too much light.

The air in your area might be a little too acidic for the coins.

remember, keep the coins aways from oxigen and impurities in the air. Humidity and sudden temperature drops are also to be avoided

Thank you for the suggestion.
I had some in ziplocks already, I will put them all in a ziplock, then back in the envelope.
I even covered them with wool scarves to protect them from the temperature. Not the best when I want to see them, but hopefully it will prevent any damage.

Quote: "Anco5"​Thank you for the suggestion.
​I had some in ziplocks already, I will put them all in a ziplock, then back in the envelope.
​I even covered them with wool scarves to protect them from the temperature. Not the best when I want to see them, but hopefully it will prevent any damage.

​Good luck collector friend!

The Euro coins are crumbling just like the EU itself

Quote: "Offa"​The Euro coins are crumbling just like the EU itself

​

The problems of conservation of coins in "proof" and/or other "high-quality" standards discussed in this thread, I thinh give us a hint: is it the purpose of a coin to be "preserved" in that "unnatural" quality?

Of course a well preserved coin is allways nicer than a used and scratched one; but at the end, we have to keep in mind that coins were and are ment to roll around the world, to pass from hand to hand (at least until the moment when e-money will cause their extinction!!!).

Thats the reason I don't bother about "proofs", "superbs", "Stempeglanz", etc.  : a real coin -hopefuly in good conditions (VF, XF, perhaps UNC) in my hands is allways better than a coin which I'm not allowed to touch because she is in a sarcophague!!

We should enjoy our collections ... not suffer with or because of them !!!

Best regards

Quote: "christianvl"​We should enjoy our collections ... not suffer with or because of them !!!

​

​Very true!!!

Quote: "christianvl"​The problems of conservation of coins in "proof" and/or other "high-quality" standards discussed in this thread, I thinh give us a hint: is it the purpose of a coin to be "preserved" in that "unnatural" quality?
​
​Of course a well preserved coin is allways nicer than a used and scratched one; but at the end, we have to keep in mind that coins were and are ment to roll around the world, to pass from hand to hand (at least until the moment when e-money will cause their extinction!!!).
​
​Thats the reason I don't bother about "proofs", "superbs", "Stempeglanz", etc.  : a real coin -hopefuly in good conditions (VF, XF, perhaps UNC) in my hands is allways better than a coin which I'm not allowed to touch because she is in a sarcophague!!
​
​We should enjoy our collections ... not suffer with or because of them !!!
​
​Best regards
​

​It's not really about "suffer" or put the coins in a graveyard, but I understand your point.
It all depends on what's a coin for you. If you see it as an object which is meant to be used, you won't care about scratches, spots or else. And this can be applied to ancient coins.
But with modern coins you can actually choose to collect coins in unc or circ conditions (which you can't clearly do with, say, Roman coins). It all depends on the criteria.
For me coins are a piece of art with an historical significance. Not all coins, of course. Nowadays you can see states issuing any sort of coin in all possible shapes to commemorate people or event they have nothing to do with, and I stay away from that. But the coins meant for circulation are, in most of cases at least, linked to national well known events or people. They have a link with the culture of the issuing country (in most of cases again). And as pieces of art, I want them in the best possible conditions, not full of scratches or dirty as they are meant to circulate.
This is my criteria.

I wish you a nice Sunday.

I had the honor and I drove through your region. I was a long time ago in the summer In the hotel in,,Agropoli,, and in the beautiful ,, Paestum ,, . dI made a trip around you to,,Capri,, Island.
You live in paradise. Only metal coins have to suffer a lot and a lot there. My colleagues on this journey are not just coins wet damp -briefs ,
coin -everything wet.
Mario, a man from Rome, was there with me, when talking about did not want the euro ,the euro ,he cursed and his hair stood .
So just waiting for new plastic coins is the solution.
A little humorous and a sample of the pile I have in the box.

Ahoj Ivan

Well, glad you liked it.
It's not heaven living here though, as for everywhere else in the world.
But travelling and seeing new places is one of the best things life has to offer.
And even if your coins are damaged, they are linked to a nice time for you, so it is worth having it.
Hope I will get to see your country as well, there are marvellous places there too.
All the best!

I understand there has not been a post on this topic for a while, but the same happened to me and I hope we can come up with at least an answer here.

 

I have a collection of world coins, euro among them, and I realized that euro cents do develop some black ressidue (easy to wipe off with a cotton swab) when stored on flips.

 

No other coin from about 800+, all on flips, developed this residue. So this must be an euro cent issue and not the flips.

 

Furthermore, the ressidue seems to appear when there is another big coin putting pressure on thw euro cent.