That it keeps Theban Queen Jocasta beautiful and young enough to get married a second time is the role that the Necklace of Harmonia plays in "Oedipus Rex."

The necklace is a gift from Hephaestus the blacksmith god to Harmonia upon her marriage to Cadmus, founder and first king of Thebes. The gift keeps the wearer from aging and becoming unattractive, but at a high price. The price is an unlucky life.

Hephaestus is the maker of the necklace. He knows what the necklace will do to the wearer. He sees it as just punishment for the infidelities of his perpetually beautiful, young wife, Aphrodite the love goddess. Specifically, Harmonia is the child of Aphrodite's extramarital affair with Ares the war god.

The necklace seems to bring initial luck into Jocasta's life by keeping her attractive enough to get married a second time after the tragic death of her first husband, Theban King Laius. But at the same time, the necklace brings bad luck because the man that Jocasta attracts turns out to be her very own son, Oedipus.