A Present for Lila

I'm trying to impress this trade ship captain Lila. I've been working on a necklace to match her lovely purple hair, but the gems have gone missing! They were there when I was showing them off to my good friend Curver last evening. We were drinking moonshine and I blacked out - when I woke up the gems were gone! They must have been darn good thieves, because Curver didn't see anything. Her ship is coming in tonight, and I really need three nightstones to get her present done. Help me out here!