In Sanskrit, Vajra means both thunderbolt and diamond. It symbolizes irresistible force and energy (the thunderbolt) and indestructibility (the diamond, also as an image of firmness and purity). In the tradition of Vajrayana Buddhism the vajra is also a small club with two ribbed spherical heads representing spiritual power and endless creativity; in the early Rigveda writings it is used by the deity Indra as a weapon to destroy evil and unhappiness with lightning, thunders and storms.