Doing some searching tonight and I stumbled upon this coin. It's a really cool example of how verdigris can develop from a fingerprint. Note the termination points of the print, there's a verdigris spot at the end of each line in the print.
I've noticed the same thing. I had a batch of 60's Canadian cents that had the same effect. If I can remember what batch they're in, I'll post a few pics.
The salt on your finger prints starts a reaction that only gets worse with time. Always wash your hands before you touch your BU coins. Repeat as necessary. http://imgs.inkfrog.com/pix/coop49/1909_Cent.jpg http://imgs.inkfrog.com/pix/coop49/1941_Struck_through_Wire.jpg
Now don't get the newbies disease " Are we there yet?". I know many think that the print is caused by the ridges of the fingerprint whorls rather than the valleys, but I think the opposite as the component that causes the corrosion are the merocrine sudoriferous glands which secrete mainly salts and water, which collects in the depressions, since the ridges are used for gripping. The end verdigris is probably caused by the sweat being squeezed out between the coin and the valleys and deposits outside the pressure area. IMO. Jim
I'm a bit bumbed. This evening going through nickel rolls I found a beautiful rainbow on one-half of the obverse and verdigris on one-half of the obverse. I may put the coin through the double dip in acetone. Thad, my understanding is that the acetone will only stop the spread of the verdigris, right? The green will still exist---it just won't spread, right? Will the acetone stop or ruin the rainbow? I'm wanting to keep the nickel for its rainbow, but I don't want to keep it if verdigris continues to spread or fear it may 'contaminate' other coins in my collection.
No, acetone will not remove or stop verdigris. However, it will dehydrate it and slow additional formation to a crawl if you store the coin in something like an Air-Tite holder immediately after rinsing. Be sure to keep all coins with verdigris far, far away from your other coins. It can absolutely spread from coin to coin. I've found a couple "mated pairs" of cents that prove verdigris can spread by contact.
I'll just kiss the rainbow goodbye. I don't want a coin with the green monster staring back at me. Thanks for the info, Thad.
In what manner to conserve? Simple 2x2 or snaplock or ?? to get rid of verdigris? By the way, I can't wait to see your verdigris book when published.