Well a friend of mine was recently looking to purchase the 2015 dimes from the March of Dimes set. He said it’s amazing how many have a brown toning to them now. I wonder what’s causing that? So I told him I bought that set that year and had it stashed away in a climate controlled place. I took my set out today to examine out of curiosity. As you can see, mainly where the backing of the velvet flap has been resting on the what I would call “pot metal” underneath, there’s active corrosion after 7 years. So I took them out of this. No brown toning on the coins. The RP has a little hazy spot on cheek that would probably make it a 69. The other two could probably grade out at 70s. Just fyi if you have this set. I doubt any long term R&D testing goes into this stuff to see how materials will interact and they’re not going to use aluminum because it might cost a few pennies more. Its ridiculous. At least the back of the velvet holder was enclosed. I will leave them in that and store it without the clamshell.
Good thing you checked. I have several silver coins from the mint, that came in the blue velveteen display and they tone in a very short time.
The Mint used that blue velveteen on many of the their coins. Does anyone know if there has been damage on more recent coins?
Quantity not quality. Seems to be the U.S. Mint's motto for some time. I've voiced this very matter over the past few years, by e-mail/actual letter and telephone to no avail. Simply put, they do not care.
I just remembered this thread, and I've been doing inventory, and decided to check my March of Dimes set. And a 2012 commemorative. Both show rust like above. Otherwise, the packaging is lovely. But should we stop storing these in the original packaging? (by the way, this is in Michigan - not usually humid, and in an area with a de-humidifier when it is humid)
I'd like to think the rusting metal cases are sacrificially protecting the coins inside, but I'm afraid the chemistry doesn't work that way.
Good to see the obverse of yours held up. How about the reverses? The OP, @Vess1 also showed decent obverses. His reverses on the other hand didn't age quite so nicely.
I've got three 2015 March of Dimes sets and each set exhibits some of the corrosion mentioned above, but to a limited degree. I also pulled out an 2000 Leif Erickson/10 Kronner set (which contains similar packaging to the 2015) and there is limited corrosion in that set as well. I wonder if it's more due to the way the mint stores this packaging and not so much in the way that we are storing these sets. I keep all my stuff in a cool dry place.....
On the 2015 set the plastic completely encloses the capsules essentially providing a barrier from the corrosion taking place underneath. But the corrosion must release something into the atmosphere of the case that if not opened for years, could make its way into the capsules and could be causing the discoloration. Not all these sets will be stored as good as others to prevent temp changes and humidity build up. As stated earlier, I left mine in the capsules, in the black plastic holder but removed that from the clamshell and set the clamshell box aside.
It's actually the other way around -- the corrosion takes oxygen (and possibly traces of other gases) out of the atmosphere of the case, and locks them up in a solid compound.
