obsidian: glass formed by volcanic eruptions

obverse: the "heads" side of a coin

Old Kingdom: Egyptian chronological term for Dynasties 3–6; around 2750–2222 B.C.

oinochoe: Greek pitcher, usually for wine

Olympia: site of the Greek sanctuary of Zeus to whom the Olympic Games were dedicated and where the Games were held

Olympus: mountain in the north of the Greek mainland, believed to be the home of the gods

Osiris: Egyptian god of the underworld and the dead; brother and husband of Isis; brother of Nephthys and Seth; father of Horus; he was associated with death and resurrection; his cult center was located in Abydos