Headrest amulets were a substitute helping the deceased to rise his head for resurrection. These amulets are mainly in hematite or other dark stones such as obsidian, diorite and basalt1. Headrests amulets were only found in royal burials up to the Third Intermediate Period but became very common mummy amulets from the Saite Dynasty 26 onwards1

Hematite L 1.9, H. 1.1, D. 0.7 Late Period MET #10.130.1832

Hematite L 2.4, H 1.5, D 0.7
Late Period
World Museum
Liverpool #1977.112.268

Hematite L 3.2, H 1.9
New Kingdom-Late Period
© The Trustees of the British Museum #EA8307

References

1Andrews C. Amulets of Ancient Egypt, 1994, pp. 95-96 and Fig. 95