I recently completed the first silver coin I've ever cleaned(with a lot of coaching and advice from a professional) and thought I'd share. The coin is a very
rare Crawford 90/2 anonymous
victoriatus, a
type missing from many RR
collections and one that I might not have ever found another example of
had I ruined this one. My goal was to clean it as conservatively as possible both because the metal in these is debased and I wanted to be careful not to do anything that wasn't necessary as far as chemical cleaning and the
reverse was struck with a fairly worn die as evidenced by the weakness and multiple small die breaks so I opted for a very careful approach.
I spent close to a month slowly cleaning the dirt and other grime off using DW soaks and a soft toothbrush first, with toothpicks used to remove the dirt from some details. This revealed mostly nice metal with
toning in some areas but also a bunch of iron oxide that especially on the
reverse was unsightly and obscuring some details and the gentle cleaning method I was attempting wasn't touching it. I used a dilute citric acid solution (half and half lemon juice and boiling water) with the electrolytic reduction method where I placed a folded piece of aluminum into the bottom of a
bowl with the coin and poured the heated solution on top of it. I only let this go for three minutes which was enough to weaken the iron oxide to the point that most could be removed with the soft toothbrush. The remainder was left on the coin as I felt that it gave a nice contrast and the solution was beginning to remove
toning in spots that didn't originally have iron oxide covering them and I did not want to completely strip the coin to bare metal. I then used DW and baking soda to neutralize the acid and tben a DW rinse and another soak to remove anything further and a quick trip in the oven at 200f to fully dry to coin.
Please let me know your thoughts. As I said this is the first silver coin I've ever personally cleaned but I think it came out as well as I could have hoped.