This glass jar is one of several discovered by Henry Layard in his excavations at the Assyrian city of Nimrud. No close parallel can be found, although there are similarities with the Sargon Vase. The jar was cast, probably by the lost wax technique, and then ground and polished. The same concentric grinding marks occur inside the vessel and, like the Sargon Vase, the centre of its base is slightly convex. Its handles have parallels dating from the eighth to the sixth centuries BC and it may be part of a Phoenician tradition. The origin and beginnings of glass making are only vaguely known. Glass is one of the earliest artificial materials made by man; glazed objects are known in Mesopotamia from the late third millennium. However, it was not until around 1600 BC that the technology expanded, with the use of special tools and the inclusion of different metal oxides to provide a range of colours.