What is the name of the jewel among the Imperial Regalia of Japan?

The jewel among the Imperial Regalia of Japan is Yasakani no Magatama.

It is one of the Three Sacred Treasures, alongside the mirror Yata no Kagami and the sword Kusanagi no Tsurugi. Together, these objects symbolize the legitimacy and continuity of Japan’s imperial institution. The jewel is traditionally associated with benevolence or virtue, while the sword represents valor and the mirror wisdom.

According to Shinto and imperial mythology, Amaterasu gave the regalia to her grandson Ninigi when he descended from heaven, establishing a sacred line of transmission to Japan’s emperors. The name Yasakani no Magatama is commonly translated in connection with a curved or comma-shaped jewel; magatama are distinctive ritual ornaments known from ancient Japan.

Unlike many famous historical objects, the regalia are not ordinary museum pieces. Their sacred status means the public cannot inspect the originals, and descriptions of the jewel’s exact appearance remain partly traditional and conjectural. “Magatama” alone is a broader category, not the complete canonical name of the imperial jewel.