Iris inlay 18-3-120 fits perfectly into this eye; packed together. Likely from a sarcophagus(?).
From Nuri, pyramid XXXI (Saka'aye), room A. 1918: excavated by the Harvard University-Museum of Fine Arts Expedition; assigned to the MFA by the government of Sudan.
Harvard University—Boston Museum of Fine Arts Expedition
Nubian, Napatan Period, reign of Nasakhma or Malowiebamani, 468–435 B.C.