Ancient glass making stretches from 1500 BC to AD 500, beginning initially in Mesopotamia. Glass objects made in early periods were predominately found in Mesopotamia and Egypt. In ancient Egypt, artistry was already highly refined during New Kingdom- King Tutankhamun’s gold mask itself was inlaid with coloured glass beads. Glass was considered a luxury product and reserved for use by the elites. However, with the advent of glass blowing invented in ancient Sidonian Phoenicia and applied widely in Roman glass production during the Augustan period, glassware became affordable and widely used by ordinary Romans. Bottles, household containers, and tableware in a variety of shapes, sizes and colour were now readily available.
Made up from a majority of silica, different coloured glass can be achieved through the addition of metal and minerals. For instance, cobalt-based compounds yields blue glass; copper alloys yield green glass; calcium antimonate produces an opaque white colour and lead antimonate gives an opaque yellow colour. The most commonly found blue-green hue is a result of the presence of iron oxide impurities in the sand used in the production of natural Roman glass. The exquisite iridescence on archaeological glass is a result of the chemical weathering of its surface by slightly acidic water presented in the soil in which it is buried. This serendipitous embellishment attests to the life story of the object.
To find out more about Roman glass, please see our relevant blog post: Ancient Roman Glass and Collecting Roman Glass.