A magatama is a curved, "comma-shaped" bead or jewel, usually worn on a necklace. Often made of jade, magatama were produced in prehistoric Japan, and are associated with ancient Japanese mythology. (Similar jewels were found in ancient Korea, where they are called gogok.) A famous example is the Yasakani no Magatama, one of the three imperial regalia of Japan. Sometimes worn for its religious meaning, sometimes just as a fashion accessory.
The following tags implicate this tag: magatama_earrings and magatama_necklace (learn more).