I'm not sure if you've misunderstood my point VC, I'm not talking about oxidation in the common sense but, rather, how can it be determined that "verd" is stable just from looking at it?'Bubbling' starts somewhere, of course, but it has a beginning! How is it determined, as BRG has confidently done, that the process has ended? This is what I'm interested in! I don't believe the green spots are Verdigris at all. Thus, I don't believe they are active in that sense. True verdigris is a reaction of acetic acid with copper, and has a certain "bubbly" look to it as VS described. These few tiny green spots simply don't appear as such, and have no signs of continued reaction with the surface metal (e.g., the lustre is still visible microscopically underneath the translucent green spots). Oh, right, that makes sense, if you don't believe it to be verdigris! Claiming stable verdigris under magnification is altogether a different animal! It might just wipe off with a bit of acetone?