With greenish blue tinge. Belonging to a popular series of first century ribbed cups created by mold-blowing, with deep spherical body decorated with sixteen fine ribs, flared lip and ground rim. Its surface has been fire-polished.
cf. Hermitage, Ancient Glass in the Hermitage, Nina Kunina, no. 210, p. 295; Pittsburgh, A. Oliver, Ancient and Islamic Glass in the Garnegie Museum of Natural History, nos. 39-40, p. 53; Oppenlander, Axel Von Saldern, Glasser der Antike, Sammlung Erwin Oppenlander, no. 265, p. 101.