This is a fragment of a clenched right hand holding a heka scepter, and the edge of a cloak, probably from a figure of a king in a Sed festival cloak. The stone is grayish-green greywacke.
From Nubia (Sudan), Kerma, K X corridor 9-1. 1914: 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