This stone amulet is perfect. The amulet represents the djed-pillar. The pillar, which symbolized the spinal column of the funerary god Osiris, was the hieroglyphic symbol for stability.
From Giza: G 7112 Mummy [Excav. date] Jan. 22, 1925 Phot. B 5802/3. Excavated by the Harvard University–Museum of Fine Arts Expedition; assigned to the MFA by the government of Egypt.
Harvard University—Boston Museum of Fine Arts Expedition