Stains on Druzy Ring

[MorgannCarol]

I recently bought a ring at an antique store. The guy working there had no info on the stone, but I saw potential in the ring, and it was a great price, so I bought it anyway. It appears to be some type of druzy stone. I have cleaned it up significantly just using mild soap and a very soft brush, however there are three deep, black stains on the stone. Any ideas what this is from, and what I can use to clean it? There’s also a black mark down the side of the stone too. I’ll try to attach pictures to clearly show what I’m working with. (I am in now way a professional so any advice is welcome!)
Before:

Now:

 

[stracci2000]

It almost looks like it was in a fire. The 3 spots look like burns and all the black in between the texture on the stone....soot??
The sterling looks pitted, as well.
Other than what you've done so far, I'm not sure what else to tell you.
You could try using a needle to pick some of the black away, and try scraping those black marks on the side of the stone, they may come off.
Sometimes jewelry just can't be saved.

 

[PintoBean]

I think the marks add to the story of the ring. Where it as is. It's cool the way it is.

 

[Bron357]

Hi, maybe it could be a synthetic onyx? It looks more like it was “all black” originally and the coating (?) has worn off. Shame I’m here in Australia, I have a stack of onyx pieces from signet rings (long story) and I’m bound to have a piece that would fit that I could give you.