Scientists Replicate Ancient Roman Lycurgus Cup's Color-Changing Effect

Scientists at the University of Sheffield have successfully replicated the color-changing effect of the ancient Roman Lycurgus Cup, a 1,600-year-old masterpiece known for shifting from jade green to ruby red depending on the light. The breakthrough provides a repeatable recipe for the first time, solving a centuries-old mystery. Source: Gizmodo Source: The Guardian

The Challenge

The Lycurgus Cup, housed in the British Museum, is a rare Roman cage cup made of dichroic glass. Its figurative design depicts King Lycurgus being tormented by Dionysus. Previous attempts to reproduce the effect had limited success. Source: The Guardian The Sheffield team, led by Dr. Lisa Hollands, used a fragment of the original to derive an ancient recipe. Source: The Guardian

The Science

The color change is achieved through nanoparticles of gold and silver, about 50-80 nanometers across, embedded in the glass. When light is transmitted, these particles block blue and green wavelengths, allowing red and orange to pass through, creating the ruby red effect. When light reflects off the surface, the particles scatter the light, giving the glass an opaque green appearance. Source: Gizmodo Source: The Guardian

The Result

Dr. Hollands described the work as "a labour of love" and "magic." Source: The Guardian The team commissioned glass artist Elliot Walker to create a contemporary sculpture that pays homage to the original. It will be unveiled at the Millennium Gallery in Sheffield from November 6-15 before a permanent display at the Turner Museum of Glass. Source: The Guardian Ian Freestone, emeritus professor at University College London, noted that while a similar effect was replicated in the 1960s, the Sheffield project is "more ambitious and more precise" and closer to the actual shades of the Lycurgus Cup. Source: The Guardian