Vajra (Devanagari: वज्र; Chinese: 金剛 jīngāng; Tibetan: རྡོ་རྗེ། dorje; Japanese: 金剛 kongo) is a Sanskrit word meaning both thunderbolt and diamond. it is also a common male name in Tibet and Bhutan. Additionally it is a symbolic ritual object that symbolizes both the proprieties of a diamond (indestructibility) and a thunderbolt (irresistible force).

The vajra is used symbolically by the Dharma traditions of Buddhism, Jainism and Hinduism, often to represent firmness of spirit and spiritual power. The use of the vajra as a symbolic and ritual tool spread from India along with Indian religion and culture to other parts of East and Southeast Asia

Read more about Vajra:  Early Descriptions, The Vajra in The Puranas, Vajra in Vajrayana Buddhism, Symbolism