diamond-pounder ［金剛杵］ ( vajra;  kongō-sho): Originally a kind of weapon used in ancient India. It is so called because of its legendary hardness—it was thought capable of destroying any other weapon, as a diamond is impervious to all other materials. In the rituals of Esoteric Buddhism, the diamond-pounder symbolizes the firm resolve to attain enlightenment, which can destroy all illusions. This diamond-pounder, or vajra, usually made of iron or copper, is slender in shape with pointed ends. There are usually three types: a single-armed, a three-pronged, and a five-pronged diamond-pounder. Among these, the three-pronged pounder represents the three mysteries, and the five-pronged pounder, the five kinds of wisdom possessed by the one Buddha Mahavairochana or by five Buddhas, respectively.