This is a gray granodiorite stele fragment with two parallel incised faces, both with two partial horizontal lines of incised Meroitic script seperated by incised register lines.
From Nubia (Sudan) Gebel Barkal, B502 I. 7. 1919: 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