Blue color of glass moves date up to 1st century CE. Updated from 3rd century CE per Professor Sarah James, Classics. BRS, 11/9/17
The shape of this jug ... (... describes as ‘bomboid’) is straightforward, yet it is difficult to classify. Isings Form 120a has a small base ring, but not a point. The shape of the body is closer to Form 60 (amphoriskos with a pointed base). Direct parallels are not forthcoming. Mariacher, pl. 17, Hayes, no. 284 and Constable-Maxwell Collection, lot 255, have globular bodies rather than ovoid, and Hayes, nos. 286 and 339 have similar bodies except for the flattened base and pour spout. Hayes, no. 415, is close in shape, save for the ribs on the body. Perhaps the most similar is Charleston and Archer, no. 8, which in all respects is very close to this jug except for the flattened based. - Ancient Glass in the University of Colorado Museum