Will acetone wreck a brown copper coin?

[Hoot]

I had a large cent that someone had obviously dipped in Blue Ribbon or some such cleaner, and had a bit of an oily coating to the surface. I dipped the coin in acetone to remove the coating and now the coin looks like dog-doo. Was this the acetone? Was the coin beneath the "preservative" rotten in the first place? Does acetone wreck the natural patina of brown copper?

 

Fortunately, the coin was not a big-value item. Lessons, lessons...

 

Hoot

[spiny]

I had it turn the residue in the protected areas a whitish color on some circulated coppers. I put them in mineral oil and the color returned to normal. Once I removed the residue, they were fine after an acetone rinse.

[TomB]

It wasn't the acetone. The Blue Ribbon was probably masking verdigris or some other disease of copper. Once the acetone removed the residual Blue Ribbon it then may have also attacked the underlying damage.

[Hoot]

Thank you spiny and Tom!

 

Hoot

[kryptonitecomics]

I haven't had any problems with acetone and copper coins before.....