Here is a beauty!  This is a rare domed blue moonstone cabochon set in a classic prong setting. I believe this is from 1950s.  The rhinestones are sett in what looks like two ruffles.  One set is bluish and the other pinkish.  It measures 2 1/4" round.   Whether pinned to a lapel, scarf, or hat, this original piece promises to add a touch of sophistication and retro flair to any outfit.