It's not standard arabic. The last letter doesn't come close to matching any arabic letters. the other three are shared in a few languages. It is definitely Middle Eastern. I'm betting its a persian language. Probably Farsi. Farsi and Arabic share most of the alphabet Sanskrit is super ornate so i don't think thats it. They way that you took the picture make the letters upside down and you read it right to left. But i cant translate it. sorry.
Oh yea i recognize that ring as soon as i saw it is a Graduation ring from the planet Zorcone it has the name of the owner inside but i cant see it to good it must of been lost during a visit to our planet the year of Graduation was 1016 BC our time its made of 52kt Zold pretty common mineral on that planet J/K really nice find that's a tuff one to figure good luck HH Jim
A colleague of mine originally from Iran told me that the letters on the ring are a prayer from the Koran, called "Van Yakut". The prayer is supposed to keep you safe. Anything bad happen to you since you have had it in your possession? If not, she must be right!