Aetites

[5]The American Geosciences Institute defines the eaglestone as "a concretionary nodule of clay ironstone about the size of a walnut that the ancients believed an eagle takes to her nest to facilitate egg-laying.

"[6] According to Pedanius Dioscorides (5.160), the aetite should be fastened to the left arm to protect the fetus; at the time of birth, it should be moved to the hip area to ease delivery.

[8] Pliny the Elder describes four types of aetites in his Natural History[9] and outlines their magico-medical use: Attached to pregnant women or to cattle, in the skins of animals that have been sacrificed, these stones act as a preventive of abortion, care being taken not to remove them till the moment of parturition; for otherwise procidence of the uterus is the result.

The fourth-century magico-medical text Cyranides also claims that the aetite worn as an amulet can prevent miscarriage caused by female demons such as Gello.

One medieval French source says that the stone "is pierced through the middle, and is round, about as large and heavy as a medium sized egg, glassy in appearance, and is to be found in the fields.

The Italian Renaissance philosopher Marsilio Ficino ascribes the aetite's ability to ease childbirth to the astrological influences of the planet Venus and the Moon.