Chemistry Of "Jungle Toned" Cash Coins

Firstly, two weeks in acetone is about two weeks too long - if it doesn't come off after just a few minutes (an hour at most), it ain't gonna come off in acetone. The only negative side-effects I've heard about acetone have come from people soaking bright copper coins for prolonged periods in bright light.

As for what's happening - I don't know. Acetone dissolves anything organic - that's "organic" in the chemical sense, not in the "pesticide-free-food" sense. So if the dirt the coins were buried in was high in organics - such as decaying plant matter, acetone might have an effect. But I can't say I've heard of this happening.

It's also possible you've got a case of "fake patina" - if the locals want to give a fake or overcleaned coin that authentic jungle look, they'll take some old green copper, crush it up, add some glue or resin and paint it on the coins. Acetone will strip fake patina right off, but should leave authentic patina alone.

What's actually happened to the green stuff that used to be there? Has it dissolved away, changed colour into the red stuff, or simply fallen off?

I always wonder why people use acetone as it is somewhat polar. I would think diethyl ether would be better as it is one of the best non polar solvents. Water being the best polar one. If it doesn't dissolve in one of those, then it isn't going to dissolve off the coin. If you go to a pharmacy then I think you can get diethyl ether... you might have to tell him what you are doing though. Otherwise he might think you are running a chemistry lab in your house :). Also, be careful with it as it has a low boiling point (i have had to fly out of a test tube more than once)

-SWUSC

I suspect that this is what was on the coin too. Many people have done things like this to make many metalic objects appear as an antique. I know I once purchased an metallic oil lamp that appeared to be really, really old with all kinds of such greenish, blackish discolorations. On a closer inspection at home I found, almost gone from the stuff, a notation that said "Made In China"
And as to Acetone in the sun effects. I saw that post some time ago. I experimented by putting numerous coins in Acetone and placing in a darkened garage. Nothing happened. Then moved the jar into the Sun for many days. Still nothing. After weeks of soaking those coins, none were effected except a dime did look newer. I don't know who or why someone made that web site about that but it was a joke. Acetone in the Sun is just Acetone in the Sun. Has no effect on Copper. Of course if left in for several hundred years there may be some effects.