Amber-working was a highly developed art in ancient Italy. The special qualities of the material must have been responsible for its popularity from the late eighth century B.C. into Roman times. Technical analysis has shown that amber originated in a limited area near the Baltic Sea and was traded down along the major rivers of Europe and over the Alps. The mystique of amber must have derived partly from the remoteness of its source as well as from the organic inclusions trapped within the resin and the fact that it is always warm to the touch. Its color and the fragrance produced when it is burned distinguish it further. These features are particularly appropriate to a thunderbolt, so potent and so thermodynamic.