Glass vessels of this type were extremely popular across the Roman Empire, used in everyday life as container for oils, balms and perfumes, but also used in funerary practice, hence many unguentaria have been excavated in graves and funerary chambers. Blow glass was originally translucent, featuring a plain, light green-blue colour. Minerals were added to create more interesting hues and colour combinations. The pearly iridescence featured on this beautiful example of Roman glassware, was not intentional, but a result of weathering on the glass surface. Many factors would have contributed to the creation of layers of colourful iridescence, such humidity, water or the type of soil the glass was buried in.
To find out more about Ancient Roman glass please visit our relevant blog post: Ancient Roman Glass.