The Vajra is a legendary and ritualistic weapon, symbolizing the properties of a diamond (indestructibility) and a thunderbolt.
A Tibetan vajra (club) and ghanta (bell)
Mahakala holding a kartika with a half-vajra handle
Indra's vajra as the privy seal of King Vajiravudh of Thailand
Five Vajrayana ritual objects at Itsukushima Shrine: a five-pronged short club (vajra) (五鈷杵, gokosho), a pestle with a single sharp blade at each end (独鈷杵, tokkosho), a stand for vajra pestle and bell (金剛盤, kongōban), a three-pronged pestle (三鈷杵, sankosho), and a five-pronged bell (五鈷鈴, gokorei).
A thunderbolt or lightning bolt is a symbolic representation of lightning when accompanied by a loud thunderclap. In Indo-European mythology, the thunderbolt was identified with the 'Sky Father'; this association is also found in later Hellenic representations of Zeus and Vedic descriptions of the vajra wielded by the god Indra. It may have been a symbol of cosmic order, as expressed in the fragment from Heraclitus describing "the Thunderbolt that steers the course of all things".
Zeus' head and thunderbolt on a coin from Epirus, 234 BC.
The thunderbolt pattern with an eagle on a coin from Olympia, Greece, 432-c.421 BC.
Zeus' head and thunderbolt on a coin from Capua, Campania, 216-211 BC.
Neo-Attic bas-relief sculpture of Jupiter, holding a thunderbolt in his right hand; detail from the Moncloa Puteal (Roman, 2nd century), National Archaeological Museum, Madrid
