Definitely a hellenic coin, don’t know which ruler, which kingdom. I’m asking if its possible to remove the bronze disease.
You can definitely remove a good amount of the ‘crud’ from this coin - depending on how (gently) brutal you’ll allow yourself to be!
Lol - well you do have to ask yourself at some point in how much you want to ‘do the right thing’ and leave a coin, versus how much you want to explore it a little further and attempt to expose the surface detail and lettering etc
Removing bronze disease can be done easily and inexpensively. First, use something pointy and soft, like a toothpick or locust thorn, to remove all the powdery deposits you can. Then buy a gallon of distilled water (DW). Soak the coin in around 1 to 1 1/2 cups of distilled water for a couple of days, remove the coin, blot dry and then place it back to soak again in fresh DW. Repeat this process for somewhere between 2 weeks to a month. The longer you do this, the better your chances of getting it all out the first time. At this point, some people bake the coin at around 200 degree Fahrenheit for an hour or so to drive out all the moisture, but I just let it air dry. Let the coin sit out someplace where you will see it often for about 3 months or so to make sure that the bronze disease does not return before placing it in a holder and adding it to your collection. About 90% of the coins I've treated this way have been cured after one of these treatments. A few coins needed a second treatment of the exact same process. I've never had a coin that needed a third treatment.
I would recommend treatment. I have one of this type. Seleucus I Mint: Antioch 312 to 280 BC Obvs: Apollo laureate right with long hair. Dotted border. Revs: BAΣIΛIEΩΣ ΣEΛEYKOY, Athena Alkidemos/Promachos in Corinthian helmet brandishing thunderbolt/spear and holding shield. Anchor to right. AE 22mm, 8.5g. Ref: SNG Isr.12.5, SC 19.15B(1)
It is always possible to remove bronze disease and the continued existence of the coin requires it be done but what you will be doing is more amputation than treatment. You can not turn what was diseased metal back to solid and healthy state. What is left when you are finished will be horridly ugly and not worth owning by many standards but the other choice is to put it out of its misery. "They Shoot Horses, Don't They?" My Alexandrian tetradrachm of Volusian was a bronze disease victim. It was spared a bullet in the head by it being very rare and having a face still relatively unscathed. It will never look better and could relapse if the treatment was faulty. Your coin is an opportunity to see what you can do but success and failure will be a matter of standards more than miracles.
I would pass this coin.The time and effort to "cure" it might be invested in better coins or reading. Good luck anyway.