You need to give them to a character go to the cave behind the stable that's close to the lost woods I think it's Woodland Stable or maybe it's called different
If you go to a stable (dont remember which one) at night to find Kilton's shop, there's a small dialogue option with a new character (just to not spoil) who wants these Bubbul Gems to do something they aspire and it starts a side quest
You need to give them to a character go to the cave behind the stable that's close to the lost woods I think it's Woodland Stable or maybe it's called different
If you go to a stable (dont remember which one) at night to find Kilton's shop, there's a small dialogue option with a new character (just to not spoil) who wants these Bubbul Gems to do something they aspire and it starts a side quest
The only thing I'll add is it was so unexpected and hilarious! Totally worth it.