Vintage Sterling Ring with Turquoise

I don't know anything about this ring! It is marked "Sterling". There are no other marks that I can see.
The band is adjustable. Usually, I stay away from adjustable rings but this one kind of spoke to me :)
The stone appears to be a real turquoise but might have some damage. It looks like there are some fine lines across. It doesn't matter to me; I still think it is a nice addition to my collection.
I think that the ring dates somewhere around the first half of the last century, but I am not sure.

Thanks for looking:)