1995-D Nickel Redistributed Copper Or Alloy Issue

Hi All,

I'm contributing to a condition phenomenon I found on one of your previous threads titled "2006-D Jefferson nickel With Bright Coppery Patches"

http://goccf.com/t/455117

Sorry that the file size restrictions have made these images so poor. I have some fairly high resolution images but they had to be considerably sized down to attach.

I'm a Conservator and I love a good condition issue. I've seen a lot of metal objects/art/artifacts in my time that have endured all manner of environments and anthropogenic damages, and this truly piqued my interest for a coin in common circulation. I was not expecting to see such a clear separation of the copper from the alloy, no matter what it's been through in its life. It's just a very unusual thing.....In fact, I'm testing sulphuric acid on another nickel to see if I can get something similar to happen. Sulphuric acid should preferentially attack the nickel, leaving just the copper behind to redistribute.

My first thought after throwing this under the microscope was that the copper had migrated to the surface. But then I began thinking of acid or corrosive contact, because some surfaces have clearly been "eaten" away or have some layered losses occurring. But it's perplexing because the pure copper deposits are on both intact surfaces and surfaces with layered losses/recesses.

I also can't rule out some type of composition error or mixing issue. Very often things will get made with an error or inherent vice, and they become more susceptible to attack or deterioration that they would have normally had resilience to. Most acidic contact a coin will endure in its life won't do something like this.

I see the member Silviosi put forth some theories similar to mine. I'm not sure if anyone settled on what this actually is, or if it's perhaps a combination of an error plus contact with an acidic substance post mint.

**Ignore the green corrosion products in two spots - I don't care about those. That's to be expected in deep pits and flaws