What is the green stuff on this coin?

The rim of this 1960 German Mark had a build-up of soft green crud. It pushed-up from the surface with the gentle, slow prod of a toothpick. Acetone finished the job. The surface of the coin shows no evidence of any harm such as "etching" from corrosion.

The coin is copper nickel. Any chemist wish to guess a reaction that causes this green crud to form and what it is? Thanks.

 

Log in or Sign up to hide this ad.

I see this on lincolns all the time. My guess is that it is a combo of skin oils and dirt that builds up on the surface from being handled. Seems easy to remove using a toothpick or something.

Just a guess though

 

I have some chem paper from my military days if you want to test it. If you start to get pinpoint pupils it's a nerve agent and you need to begin to administer your atropine injectors.

flashbacks......

 

Looks like the fuzz from aging and decaying imitation felt lining in some holders. Doesn't have a chem look at all.

 

Agree with desertgem. I have seen this on cabinet stored coins that have felt liners. Eventually the felt deteriorates and begins to float inside the cabinet with opening repeatedly, and attaches itself to the coin.

 

The stuff is some type of copper crud. @Evan8 has seen it on Lincolns. I have seen it on many different coin types. The pushed up (fuzz) has no visible fibers. It is the soft green crud. Similar crud is on the base of the brass snap on my leather key case and even forms on my glass frames!

I have finally become curious to discover what it is.

 

I guess it was the way I saw it in the photos that tended to make me say what I did. Different eyes, different conclusion. Mold sometimes grows like a fuzz, maybe? I've had the same problem on my belt and glasses also, ( Not fuzz, just going green ) I can only assume possibly skin oils. Actually I'm at a loss otherwise. Sorry.

 

oxidized copper, or copper sulfate. Same thing that makes your pipes turn green. aka
verdigris

 

I thought copper sulfate was blue.

 

Its blueish green. Think of the statue of liberty

 

In 1973 we called it....


it just showed up 6 years sooner then we thought....

 

If it smells like almonds it's too late. If you inject your atropine, make sure you do it in the fattest part of your leg as the needle will break a bone if it hits bone.

 

I wear glasses & never have I seen any green fuzzy funky stuff. I also clean them several times a day.

 

Oh heck no, no fuzzy stuff, just turning green, cheap metal frames. Mostly I had this problem with company paid for glasses that they cheaped out on. My new frames are SS and no green anymore.

 

OK, but with a copper nickel (alloy I assume ) rather than clad, I do not see a way that it could occur chemically, and in such small fiberous strands. Based on the photos, I will stay with my answer until someone with better photos or Analytical chemistry instruments. Jim

 

Somebody with a different body composition messing with your coin collection when you aren't home?

 

LOL, yeah no cheap crap. I'm partial to the Fossil Flexlite, I'm to active so they have to take a hit & go back into shape.

 

Yeah, Big Money been messing w/my collection.

There are no fibrous strands! Look at the first photo. It is soft green crud. I guess it is verdigris as some have said. Would like to know chemical formula for how it forms. No velvet is around.