Researchers at the University of Sheffield have recreated a striking effect found in ancient Roman glass. Their inspiration was the Lycurgus Cup, a roughly 1,600-year-old vessel that has been at the British Museum since 1958. It appears green when light reflects off its surface, but red when light passes through it.
Scientists believe Roman craftspeople produced this effect by adding extremely small particles of gold and silver to the glass. The particles scatter reflected light, creating the green appearance. When light travels through the glass, they block blue and green while allowing red and orange to pass.
Lisa Hollands, who led the project, worked with Roman glass expert Caroline Jackson to recreate a suitable base glass. Hollands then experimented with ingredients, furnace types and oxygen levels until she found a reliable method using only raw materials available to the Romans. However, the color remained sensitive to small changes: moving the glass to another position inside the furnace could alter the result.
British glass artist Elliot Walker used the material to create a sculpture inspired by Roman mythology and art. The piece will appear at the university's Festival of the Mind before going on permanent display at its Turner Museum of Glass.
