Help! Trouble cleaning a moonstone in a sealed ring

[meowkachu]

I recently got a 14k gold cabochon moonstone ring. The bottom is sealed. Somehow some grey particles got into the bottom of the ring. Since it’s sealed, I can’t clean it. I’ve tried ultrasonic cleaner and jewelry cleaning solutions, and none of them worked.
Do I have to take the stone off to clean its bottom?

 

[Daisys and Diamonds]

Can we see a pick please

 

[peacechick]

Were the grey particles there when you received it? Just trying to rule out natural inclusions here.

 

[T L]

That’s why I always advocate against closed back settings. I highly doubt you’ll be able to clean it.

If you love the gem, maybe it’s worth resetting? Or maybe a jeweler can get rid of the backing??