So cute! This tiny little ring is a slide pendant or charm. The lovely authentic Emerald is prong set. Charm is 3/8" in diameter plus the 1/8" setting. Marked 10k and tested. In excellent condition, well made, ca 1980's.
This charm is the second one left to right in the main image. They look great on a rope bracelet too. Would you like to see the other miniature ring charms?