鈷 - cobalt

ground stone tool from the late Jomon period

ground stone tool from the late Jomon period (named after its similarity to the Buddhist tokko)

three-pronged vajra flung by Kukai on his return from China to determine the Holy Land of Esoteric Buddhism

trident vajra

single-pronged vajra; tokko; dokko; copper or iron implement, pointed at both ends, used in esoteric Buddhist rituals