Green Copper Corrosion - Chemistry

When VERDIGONE™ is used properly, this is what you can achieve.

VERDIGONE™ treated 1909SVDB in NGC slab:

So what actually has been proven (which I already knew) is that TPGs will grade cleaned coins. I know if I received a slobbed coin with streaks of discoloration, I wouldn't be happy.

Today I had to do some repair work on our SEM (Scanning Electron Microscope) so I thought I'd use a Zincoln with verdigris as a test object. This is the first time I've looked at verdigris on a Zincoln!

Here's a snapshot of what I was looking at:



The verdigris appeared to have some blackish, organic material mixed in. Looking at the relative abundances of elements, I confirmed this due to the presence of carbon. I was surprized to also find fairly high amounts of sodium and chloride, which leaves me to believe the corrosion was catalyzed with good old table salt. There was also traces of potassium which is an impurity in salt (potassium chloride). Interestingly, there was almost no copper sulfate, the verdigris was mainly composed of copper/zinc chloride's and oxides.

Just thought I'd share some science.

Thad, I suspect that that area was initialized by skin secretions such as sweat since as I interpret the graph, the potassium level would be much lower and the iodide component would be seen. The carbon, sodium, potassium, and chloride levels would be consistent with perspiration. Do you have a photo of the coin itself and the area sampled? Might be a fingerprint ridge origin.

Jim

Fascinating analysis of a "Zincoln*" and I'm glad to see your 09-S VDB slabbed.
*poor Mr. Lincoln, I suppose he'd laugh...

Thanks Kurt, I hope everyone has enjoyed this thread. I wish I could have posted all my work here, it was just getting too time consuming. Now that I have the VERDI-GONE™ formula completed, I'll post little tidbits like this when I run them. I've been toying with the idea of working on some new variations, like a verdigris remover for Nickels. I've seen quite a few Jeffersons with verdigris too.

Negative guy didn't even deserve a reply. LOL. But I'll take the time to do it for you.




Everyone can see plain as day you DID say it won't slab.

Your problem is quite simple. You do not understand and won't move from your stubborn position. You can't even come up with N C S and said NCC

A CONSERVED coin has been treated with RESPECT and has not been altered at the molecular/metal level. Can't you see the beautiful coins that are being saved ? it is obvious from the pictures that any changes in patina are very minor, and usually BENEFICIAL. They look so much better! that 1909 is beautiful and was a very sad coin before.

Congrats, this is a great product. I'm surprised more work on this wasn't done sooner, you've cornered the market !