This pendant is a recreation of an ancient Roman image of Hecate. It shows Hecate driving the moon chariot across the zodiae. One of Hecate's symbols was the key, symbolizing she was mistress of three realms: underworld, earth, and starry heavens.
Photo by Snook Family Photography
See:
Deity Images: Roman Hecate
Goddesses Dictionary: Hecate
Other Images: Selene
Sacred Source Images: Hecate