I recently got this coin, but the toning is a bit darker than I would like. I am thinking about reversing the toning process a little to brighten things up a bit. This is not the same thing as dipping which removes the silver sulfide layer from the coin. This method removes the sulfur from the silver while keeping the silver in place. The method: 1. Line the bottom of a glass bowl or dish with aluminum foil. 2. Place the coin on the foil. 3. Pour a few tablespoons of sodium bicarbonate (baking soda) onto the coin and aluminum. 4. Pour in boiling water and stir lightly to dissolve the baking soda. 5. Let sit until the tarnish disappears. What is going on here? Well, what is on the coin is Ag2S. We want Ag. So we add aluminum into the reaction to form Al2S3 from Al. This does not happen spontaneously, so we need to add a catylist (baking soda dissolved in water) and energy (boiling water) into the system to make the reaction occur spontaneously. The sulfur is transferred to the aluminum, leaving the silver atoms on the coin bare. I have done this a couple of times with coins that were toned completely black, and I was successful. Anyhoo, here is the coin in question. Opinions?
The process works, but it's not going to work as you think it will. It won't reverse the thin film interference color progression in order, it'll reverse it by thickness. It's all end-state color, but some areas are physically thinner than others and will revert earlier. You'll be left with a blotchy coin which won't grade. It's an all-or-nothing process.
As I've said, I've done this before, so I know how the coin would look afterwards. I was not expecting a rainbow to pop out.
Would love to see how this comes out. BTW, when you use EZest and you smell rotten eggs, that is pretty much the same process you are doing here except the H's coming from the EZest acid instead of the Al coming from the Al foil.
Nice and original. The reverse is maybe a tad dark for me, but I'd have no problem owning this coin. I would not do the baking soda method on it.
I have been studying this coin to get an idea of what the surfaces would look like should I go with this procedure, and I think I will leave ot as is. I think that there are cleaned/polished surfaces (I doubt it is PL) underneath the tarnish, and removal of the toning would bring that out. I will leave her as she is.
That's actually what I was gonna type, until I scrolled down to your last post.... Specifically, the right obverse field would (most likely) make u kick yourself for performing this experiment.
