The Romans loved glass for its practical as well as decorative uses. Glass bottles, such as this beautiful example, were used as containers for ointments, powders, balms, and other expensive liquids associated with the toilet, especially perfumes. The small mouth of the bottle is ideal for slow, careful pouring, while glass was preferred for holding liquids, due to its non-porous, non-absorbent nature. Glass vessels are found frequently at Hellenistic and Roman sites, especially in cemeteries, and the liquids that filled them would have been gathered from all corners of the expansive Roman Empire.
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 also all affect its preservation.
To find out more about Roman glass please see our relevant blog post: Ancient Glass and Collecting Roman Glass.