AGAIN with the Silver Rings Part II!!!

Saturday afternoon after a three hour morning hunt I was still feeling the itch. So I took my son to a tot lot at a local school and did some swinging while he monkeyed around on the play equipment. I've been to this particular tot lot before, and I am guessing that someone else has hunted it and maybe still does, as it is pretty big and pretty well used and I've only found a few coins there. The story was the same this time; I found 1 quarter, 1 dime, and 5 pennies, and most of that wasn't in the chips but rather the grassy area around the tot lot. We slowly headed back to the car when I got a nice signal under a swing. I brushed a few inches of chips away with my foot and could see the glint of a silver ring! It's certainly my nicest one so far. It is very small, but it is stamped .925 and has a small cut blue stone. I doubt it has any value but I wonder what the stone is... any ideas?

That's my fourth silver ring in about 2 weeks! Where oh where is the gold?

Thanks for looking!