If I tried the OP's methods here in south Florida, with the humidity, rain, and heat, the coin is liable to end up a pile of green dust within 3 weeks. This time of year we alternate between days where outdoors feels like a boiling and humid sauna, or days where it just won't stop raining for even 2 minutes.
Which is why I try to avoid leaving bronze coins laying around in my room (or anywhere around my house for that matter). I'll take them out to look at occasionally, but then back into the dry darkness they go.
Congrats ... hey Ken, your project is comin' along fairly nicely (it is fun to watch) => I think I may have finally found something worthwhile in this frozen hell? (it looks like it may be even bigger than JA's new Ptolemy?!)
i just tried to find these coin i buried last may and had no luck at all...LOL! Q! did you come snag them?!
No photo update as there really isnt any change. As I was on the roof today cleaning gutters and smelling the truly horrible stench from the water there, I got the idea that I would take some of that rotting leaf matter and put the coin in that viscous mix. May not work, but who knows?
Ken, you're doing it all wrong, just bury it in the yard and have your descendants dig it up in 1700 years, it will be fine.
I have no doubt! I am sure there are those out there who can re-tone it and make it into a $500 coin, but I have no such abilities. No interest, either. At some point it will tone down. I'm just waiting. I can only imagine what people might think when they find a Roman sesterius in California 1,000 years from now!