The Greek vessel opened in Hesiod’s original Pandora story is a pithos. A pithos was a large storage jar used in ancient Greece for materials such as grain, wine, or oil.
Hesiod’s Works and Days describes Pandora opening a container that held troubles for humanity. The Greek word pithos does not mean a small hinged box. It refers to a substantial ceramic vessel, often large enough to store agricultural goods. This detail is the reason many classicists describe “Pandora’s jar” as more accurate than “Pandora’s box” for the earliest version.
The familiar phrase became standard through later retellings and translations. Erasmus helped popularize the Latin expression associated with a box, and English usage eventually fixed “Pandora’s box” as the conventional phrase. The original vessel, however, was a pithos.