I bought this because it looked like it was going to be an easy cleaning job like how my Carolingian denier from Venice was (a quarter of the dirt practically slid off after like 15 minutes). Unfortunately this turned out not to be the case here. The lemon juice I was using had seemingly had no effect after 12 hours, but a few parts of the black encrustation did weaken. Most of it remains however, and not only this, but in a few places on the edge the silver seems to be at risk of flaking off, as I found out the hard way when I took most of the top part off of the T in OPTIMO on the reverse when scraping the black stuff in that area with my fingernail. After, I kept it in for another two days with no effect. I'm sharing this in the hopes that I could please get help on what my next move should be in cleaning it. Anything better than lemon juice out there to remove tough black gunk on silver? Should I just leave it longer in lemon juice. Really appreciate any help. Before: After:
I dunno, but my cleaning skills would not allow me to touch this coin. It would probably be worthless when I got done. I like where you have it now, so in light of the aforementioned talents, I would leave it be
I agree with @TIF Probably horn silver. There are ways to convert it back to metallic silver but I do not have experience treating it myself. I know that one common method uses photographic fixer solution as the same reaction is used in processing certain types of film.
Thanks for the info. I really don't want to risk damaging the coin so I think I will leave it at that. At least this served as a learning experience for me.
This is a little late the party, but there's a thread on Forum that talks about using film developing chemicals (hypo), and the before/after pictures look pretty convincing: http://www.forumancientcoins.com/board/index.php?topic=79957.0;wap2
