Enkei

…These are jade axes, bi (spirits), and cong (congs). Jade axes continued to be made for a long time, and the tradition continued until around the 3rd century BCE, and in the classics of the late 1st millennium BCE they came to be called enkei (wanggui). There are indications that bi (spirits) were modeled after celestial bodies at the time, and cong (congs) have human faces carved into the four corners representing heavenly gods. …

*Some of the terminology explanations that mention "琬ケイ" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…玉製の斧，璧（へき），琮（そう）がそれである。玉製の斧は後にも長く作られ，前3世紀ころまで伝統が続き，前1千年紀末の古典中で琬圭（えんけい）と呼ばれるにいたる。璧は当時天体をかたどったと推測すべきふしがあり，琮は四隅に天神を表した人面を刻む。…

※「琬圭」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報