Medal turned darkish in display?!

[Reich]

Hi,

I was reorganizing my displays when I noticed that a silver medal that I particularily like has turned somewhat darkish and matte at the back, whereas it used to be bright and shiny before the I put it in the display.

My heart sank and I still can't believe this happened.

Before:



After:



The medal has been in this Pin display case for about 4-5 years. I have done two modifications to the display case: swapped the glass for anti-UV glass and wrapped the foam (in which the items are pressed) in black 100% cotton, which might seem like the culprit, but read on...

Some things to note:

• The entire back of the medal changed even though most of it was only in contact with unbleached cotton which is supposed to be the most neutral material.
• The front of the medal was pressed (lightly) against the glass panel of the display and does not seem to have changed whatsoever.
• The display was kept at around 50% RH for most of the time.

I have also noticed that the back of my Österreich Anschlussmedaille has changed:

Before:


After:


This one is not all that bad, but there is no more shine to it and the patina pattern is noticeably different...

I have not observed a noticeable difference on other objects of all 3 of my identical display cases, including armbands and medal ribbons, regardless of whether the objects were in contact with black or unbleached cotton.

Some questions:

• Any idea what caused this? It seems to be specific to silver, maybe some sort of mold?
• Is it restorable in any way?
• Even if taken out of the display, could whatever process is at play continue?
• Is it bad for medals to be pressed against fabric with no breathing space in a closed display for years?
• Can I somehow prevent this in the future or should I consider my display cases as unsafe and look for another display altogether?

Thanks a lot folks, absolutely any and all help is appreciated, I am at a loss here and completely shocked. I put a lot of thought & time in trying to setup some display cases that would adequately protect my items, so I feel like a total failure right now...

[LoyalHistorian]

There could be more to it then this, so please wait to see what others say. However, if it's real silver, then silver tarnishes over time and gets blacker with age. It's a chemical reaction when silver comes into contact with sulfur gases in the air. If it is tarnish, than it generally can be polished fairly easily...but I would still wait for others' opinions before doing anything. I'm not even sure that you should polish it though, because most people want real patina left on a piece. I know there are anti-tarnish fabrics that some people use to store jewelry, and it might help this situation in the future. Yet, I'm not sure if there would be any adverse effects to the ribbons on the medals...I don't know what those fabrics are made of. Might be worth researching though.

-Robyn

[Reich]

Thanks for your reply Robyn. As advised I will wait for other feedback, but in the meantime I gotta say I was happy to read that you think it could be polished fairly easily. I tried rubbing it lightly with a white cotton glove and it did stain the glove but I didn't see a noticeable improvement. Holding on for now though.

One thing however, you are right that it is normal for silver to tarnish, but I'm worried because only the back of the medal changed, and so quickly, whereas the front of the medal remained seamingly intact...

[KMMorris]

It is very normal for silver to tarnish which has happened in your example, if you intend to polish it, make sure you don't over polish it and start to take the softer top layer of silver off.
A very fine whip over with a silver cloth will remove most of the natural tarnish, but dont try and buff things out to make it shiny again.

Morris

[Reich]

Thank you very much for your reply KMMoris, that is a relief!

I'm now thinking of replacing the black 100% cotton with black silver cloth for its anti-tarnish properties. Would that be enough to prevent it from happening? Anything else I can do?

Also, does silver cloth have any adverse effect on some materials? Taking for granted that it is acid free.

I'm so happy to have learned this today, as I was actually reorganizing my displays to make room for my "new" NSDAP 15-year medal, featuring, of course, silver...