A piece of D'ni technology, actually a stone charged with with a great aount of energy. It is combustible but can be extinguished by water. Polished well, it produces bright light and can be used as a light source in special lanterns. The anniversary of the finding of the Book of Birenni was celebrated by re-enacting the search for the books by hiding fire marbles in homes and Ages for children to find. Fire marbles of various colors were on the top of each "reflecton pole" of J'nanin, as well as the path that lead to the Greenhouse.