stone that warns of danger

Exploration Stage: Negotiation Room
From: Abbot Paku
Description: I have learned many interesting facts about the violet flower, but I still don't know anything about how it makes me angry. I have a ring that changes color to tell me when danger is approaching. Let's say I put it close to the flower...it's funny. I don't remember taking the ring off, but I can't find it anywhere. Can you look for it with me?
Completed: Did you fall next to the flower in the example? I remembered. I took the ring off to do an experiment, and it seems I forgot it while I went to call you. If there is something dangerous nearby, the stone in this ring will glow to tell you. When I placed this next to the flower... instead of glowing, it darkened in color and cracked!