Oval shaped palette? with one flattened surface.
From Nuri, Pyramid XXVI F.D. "NW" corner. 1918: Excavated by the Harvard University-Museum of Fine Arts Expedition; assigned to the MFA in the division of finds by the government of Sudan.
Harvard University—Boston Museum of Fine Arts Expedition
Nubian, Napatan Period, reign of Queen Amanitakaye, 553–538 B.C.