In Hesiod’s account, Pandora was made from clay before the gods added their gifts. Zeus orders Hephaestus to shape her from earth, giving the creation episode a crafted, artificial beginning.
The clay imagery connects Pandora with other ancient creation traditions in which a deity forms a human figure from earth. Hesiod then describes additional divine contributions, including beauty, clothing, skill, and persuasive speech. Pandora is therefore both an earthen figure and a composite of divine attributes.
This question concerns the material used for her initial form, not the identity of the god who shaped it. Hephaestus is the divine craftsman in the story, while the other gods contribute qualities. Keeping those roles separate avoids a common confusion between maker, material, and gift-giver.
Later artwork may show Pandora emerging fully formed or rising from a vessel, but those scenes are artistic interpretations. Hesiod’s written account presents her construction as a deliberate act ordered by Zeus and carried out through divine craftsmanship.