I have a similar story, and me being a gunowner helped solve the mystery.
Last christmas my wife lost her stone out of her engagement ring. We thought it fell out at her office holiday party, and everyone was looking through the shrimp boat, under tables, in the parking lot etc. and it was never found.
fast forward 3 months and i was installing 2 inside the wall gun safes, i used my dremel with the drywall attachement, and there was drywall dust everywhere. i got the vacume out to clean up, and in the track of one of our sliding closet doors i saw something shiny, and almost vacuumed it up, it ended up being her stone.
it was a very special stone, we picked the stone out first , and went to many gem and mineral shows untill she found the perfect one. i actually proposed to her with the stone first, and we had the ring custom made around the stone, and the bamd was inlaid with austalian opal.
needless to say she was soooo happy i was a gun owner that day!!!