The shape and scale of this cup relates to glass patellae that are found throughout the Roman world in the late 1st century B.C. and 1st century A.D., but for the flourish of the flange below the rim, rather than carination. The shape is also known in pottery and precious metal. For the glass examples, see nos. 297-302 in Goldstein, Pre-Roman and Early Roman Glass in the Corning Museum of Glass. For a related agate cup, slightly later in date, see no. 84 in Bühler, Antike Gefässe aus Edelsteinen.