GERMANY, Braunschweig-Wolfenbüttel (Herzogtum). Rudolf August. 1666-1685. AR 12 Mariengroschen (32mm, 8,015g, 6h). Zellerfeld mint. Dated 1670. Wild man standing right, pulling branches from tree / Denomination in three lines. KM 504. 
This coin was transformed into a pendant long time ago. 
Certificate of provenance and authenticity included .