The witches and other magical creatures in the novel use organic materials such as bones, herbs, and plants as symbolic elements in their magic. Yarrow root, for example, represents protection because it is linked to healing in herbal medicinal practices. By using herbs as symbols of their applications in herbal medicine, witchcraft is grounded into real-life uses of such plants, creating a link between domestic work and witchcraft.

Bones are a symbol of dark magic in the novel, as they are a primary material used in dark magic rituals. The use of bones symbolizes the sacrifices necessary to completing dark magic spells, because their presence in the ritual necessitates that a living creature dies and decomposes. As Emilia’s conception of the morality of magic grows more nuanced, the link between bones and death is framed as not entirely negative, but indicative of the gravity of the spell being performed. 

Emilia and Vittoria’s cornicello amulets represent their status as Shadow Witches, ancestrally linked to the Wicked, as Emilia learns from Envy. They also symbolize the power witches have over the devil, thanks to La Prima’s curse, and Emilia and Vittoria’s possession of the amulets indicates their role in the prophecy of how the curse will be broken.