❓Candescent Coal

Coal formed from ancient magical organisms can sometimes display special properties. These coals are said to be the very same that light the everburning fire in a dragon's belly, though it's unclear as to whether or not that is pure mythology. Regardless of origin, it's true that they continue to burn for seemingly eternity as long as there is fuel for their fire.

These have been popping up all over lately... What could they be for?