This is a sealing stone fragment. Adhering to it is a quantity of gypsum with a seal impression which is on a mud block.
From Egypt, Giza, G7757A (tomb of Kheperre) around coffin in room X. 1929: Excavated by the Harvard University–Boston Museum of Fine Arts Expedition; assigned to the MFA in the division of finds by the government of Egypt. (Accession date: )
Harvard University–Boston Museum of Fine Arts Expedition