"In Greek mythology, Selene (Σελήνη, "moon"; English IPA: /sɛˈliːniː/) was an archaic lunar deity and the daughter of the titans Hyperion and Theia.[1] In Roman mythology, the moon goddess is called Luna, Latin for "moon"."

"In post-Renaissance art, Selene is generally depicted as a beautiful woman with a pale face, riding a silver chariot pulled by a yoke of oxen or a pair of horses. Often, she has been shown riding a horse or bull, wearing robes and a half-moon on her head and carrying a torch. Essentially, Selene is the moon goddess but is literally defined as 'the moon'."

(Wikipedia)

I would guess a chariot or a torch, but don't quote me on that.

Actually believe it or not, the symbol for Selene (Luna) is (gasp) THE MOON!!!! She is one of the three moon goddesses....Artemis (The Maiden), Selene (The Mother), and Hekate (The Crone).