Unguentaria were small perfume or cosmetics bottles made of blown glass. They were extremely popular throughout the Roman Empire, since they contained perfume and oil, considered precious at the time and often used both in private life and public ceremonies. This type of vessels was probably used also in funerary and burial rituals, hence their frequent occurrence in archaeological excavations of ancient cemeteries.
Originally, much of Roman glass vessels were modelled in bluish-green translucent colour, which resulted from the iron oxide present in the silica or the sand. However other metal oxides were added to the glass to give it different bright colours; in the case of this beautiful example, manganese would have been added to the glass to create an intense purple colouration.