I JUST found a resource here in town (NM) who replaces stones of all kinds. I bring it there, he matches and replaces. He's got floor to ceiling bins of stones organized by color and size or, if still on the jewelry item, by color. He did an AMAZING job on my grandmother's costume aquamarine choker. Charges .50 per replacement. Needless to say, I LUVS this guy!! lol