Stained Glass

Sheffield scientists recreate color-shifting glass recipe of ancient Lycurgus Cup

Researchers at the University of Sheffield have reproduced the original Roman glass-making recipe behind the fourth-century Lycurgus Cup, producing a new sculpture that mimics its ability to appear green under front lighting and red when lit from behind. The effect stems from gold and silver nanoparticles embedded in the glass, a technique discovered in 2007 to explain the cup's unusual optical behavior.