Glass was often the preferred material for storing expensive oils, perfumes, and medicines because it was not porous. The small mouth allowed the user to carefully pour and control the amount of liquid dispensed. 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 glass bottles 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. Different minerals were added to create a variety of colours; the yellow tint seen in this piece would have been created by adding antimony and lead.
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; however, the humidity, heat, and type of soil in which the glass was buried all affect its preservation as well.
To find out more about Roman glass, please see our relevant blog post: Ancient Roman Glass and Collecting Roman Glass.
