This is a rounded fragment of body part (limb?). The stone is black granodiorite with sporadic black biotite inclusions and mica, the break areas look granulated. GD5.
From Nubia (Sudan), Kerma, K X grave 1026 no.5. 1913: Excavated by the Harvard University–Boston Museum of Fine Arts Expedition; assigned to the MFA by the government of Sudan.
Harvard University—Boston Museum of Fine Arts Expedition