Glass was often the preferred material for storing expensive oils, perfumes, and medicines because it was not porous. By the 1st century AD, the technique of glass-blowing had revolutionised the art of glass-making, allowing for the production of small medicine, incense, and perfume containers in new forms. These small glass bottles, known as unguentaria, are found frequently at Hellenistic and Roman sites, especially in cemeteries, and the liquids which filled them would have been gathered from all corners of the expansive Roman Empire. The natural colour of Roman glass was tinted an aqua colour. Through the use of additional chemicals and minerals, Roman craftsmen were able to alter the colour of glass. This clear glass was created through the addition of antimony or manganese oxide, which oxidised the natural aqua Iron II oxide to Iron III oxide. The new iron III oxide, although slightly yellow in colouring, was much weaker and thus gives the illusion the glass is colourless. The iridescence on ancient Roman glass was unintentional, and was caused by weathering on its surface. The extent to which a glass object weathers depends mainly on the burial conditions; the humidity, heat, and type of soil in which the glass was buried all affect its preservation.
Ancient Roman Glass Unguentarium
A delicate Roman unguentarium made from colourless glass, with a slight yellow tint. The flask features a globular body leading to a wide, cylindrical neck with gently flaring shoulders. The neck flares outwards to an everted tubular rim folded over the small funnel-shaped mouth. The base is only slightly flattened. The vessel is covered with a multi hued iridescence and encrustation.
Condition: Very good condition. Iridescence, weathering and some earthy encrustations to the surface. Please be aware the encrustation on the outside is susceptible to flaking off.