Dirty Coins 0

[sanction]

It is said in numismatics never to clean a coin but if dirt has set into the coin for anywhere from fifty years or more would it not eventually cause the coin to deteriorate?(this is the back of a 1937D buffalo nickel it is green mold on it I took the picture after I had created the topic.

Edited December 6, 2022 by sanction
I added a picture

[CrystalM CS]

Hello! Depending on the contaminant it can damage the coin after being left on it for a long period of time. We recommend checking out our Conservation Services page for more information on what we can do for you and your coin. I have included the link to the page below. Thank you. 

Coin Conservation | NCS | Numismatic Conservation Services | NGC (ngccoin.com)

[Coinbuf]

It is impossible to say much from your photos, heck I could not even tell what coin it is from the photo.   However, if the coin has something active on it like PVC or verdigris, those can attack and damage the surface of a coin.   My suggestion is to place the coin into a bowel of pure acetone (not nail polish remover), lightly agitate the coin in the acetone and see if the green gunk comes off.   This is a safe method to see if the gunk can be removed without harming the coin, however, it is very possible that the surface of the coin may be pitted or damaged.   If nothing happens then you may wish to look into the NGC conservation services if the coin is valuable enough to warrant the expense.

[VKurtB]

If it’s a nickel, it’s not going to be mold. It’s cupric oxides and/or sulfides, also known as verdigris. And it CAN permanently damage the coin’s surfaces. 

[sanction]

Thanks Kurt