The magatama was also transmitted to the Korean peninsula, and examples of magatama made from amazonite during the Mumon pottery period from the 6th century B.C. to the 3rd Century are known.
朝鮮半島へも伝播し、B.C.6世紀から3世紀初頭の無文土器時代に微斜長石天河石製の勾玉が見られる。 - Wikipedia日英京都関連文書対訳コーパス