How Exactly Should I Go About Putting This Seated Quarter In Acetone?

The acetone can only remove organic contaminants. It obviously helped the green spots. The new pic you posted reminds me of the same coloring/look as the closeup pic you posted before: "brighter". I would think a 24 hour soak would about take off everything it is going to at present.


Sometimes I have found the gunk in direct contact with the acetone will "protect" some of the lower gunk. So I use the porcupine quill method I mentioned earlier in this thread. I then re-soak.

If you do use the quill method, I have not used it on a seated coin simply b/c I don;t have nice enough ones that ever needed it. The only time I have seen a scratch from a quill is if the dirt I am removing is hard enough to scratch the coin and it gets in between the quill and the surface. I am always using a microscope when doing this and the moves I make a very small and short (like scooping the gunk out the loops of an S mint mark). I am very careful when on a field so if there is a start of a mark (rare occurrence in my hundreds of times of doing this) I stop immediately.