--- title: "The Lycurgus Cup Changes Color Depending on Lighting" url: https://newscentral.site/the-lycurgus-cup-changes-color-depending-on-lighting/ language: en publisher: "News Central Site" section: "Science" published: 2026-11-02T11:00:00.000Z updated: 2026-11-02T15:57:13.138Z id: 8e65b373-25c1-4dc4-b35a-a838b41d0847 source: "Live Science https://www.livescience.com/archaeology/romans/lycurgus-cup-a-roman-glass-goblet-made-with-ancient-color-changing-nanotechnology" attribution: "Link to https://newscentral.site/the-lycurgus-cup-changes-color-depending-on-lighting/ and name News Central Site when you quote or summarize this story." --- # The Lycurgus Cup Changes Color Depending on Lighting A Roman-era glass goblet discovered in a British museum has been found to have a unique property where its color changes depending on lighting. A Roman-era glass goblet has been discovered to have an extraordinary property: its color changes depending on whether light shines from the front or back of the object. The Lycurgus Cup, as it's known, appears jade green when illuminated from one side and ruby red when lit from the other. The cup is a remarkable example of ancient Roman glasswork, part of a rare category called "cage-cups. These goblets were made by cutting and grinding decoration into thick glass, leaving small bridges to ensure the design remained intact. Only a few cage-cups remain today, highlighting their exceptional craftsmanship. Despite its significance, the Lycurgus Cup's history remains shrouded in mystery. Its origins are unclear, with experts unsure whether it was created by accident or intentionally designed to change color. The cup has been owned by the Rothschild banking family since the mid-19th century and is now part of the British Museum's collection. The cup weighs approximately 6 pounds (700 grams) and is considered a remarkably well-preserved example of Roman glasswork. A study published in 1959 described its unique construction, noting that it would have been made by grinding decoration into thick glass, leaving small bridges to support the design. The Lycurgus Cup's estimated date of manufacture is believed to be around the fourth century, possibly crafted in Italy. However, it is thought that the bronze frame, which forms the stem and rim of the goblet, was likely added much later, specifically during the 19th century. The cup itself features a depiction of the myth of Lycurgus, king of the Thracian tribe known as the Edoni or Edonians. According to legend, Lycurgus was punished for his disapproval of the worship of Dionysus, who was banished into the sea with an ax by the king. The punishment of Lycurgus is intricately linked to the goblet's design and color-changing properties. As a god associated with wine and merriment, Dionysus' influence on the cup may have been intentionally reflected in its transformation from green to red, possibly symbolizing the ripening of grapes on the vine. Few records exist of ancient Roman dichroic cups that could change color depending on the light source. One such reference is found in a second-century letter attributed to Emperor Hadrian, which describes two gift cups given for use during banquets. The rarity of surviving fragments from these mysterious glass cups has puzzled experts for years, with only a handful remaining today. Despite this scarcity, researchers have been working tirelessly to understand how ancient Romans created dichroic cups and replicate their color-changing effect. A crucial discovery was made in 1963 when it was confirmed that the key to creating dichroic cups lies in adding microscopic nanoparticles of gold and silver during glassblowing. These tiny metal particles interact with light, giving the appearance of milky-green glass when lit from the front and nearly translucent red glass when illuminated from behind. The Lycurgus Cup's color-changing effect is attributed to these same metal nanoparticles, which are significantly smaller than grains of sand. Their interaction with light creates the perception of a color change, allowing dichroic cups to shift between different hues depending on the lighting conditions. Researchers have successfully replicated the color-changing properties of dichroic glass using advanced techniques such as 3D printing. The researchers behind the Lycurgus Cup project have successfully replicated the ancient glass's color-changing properties using advanced techniques such as 3D printing. This achievement was made possible by reverse-engineering the recipe" from the original Lycurgus Cup. To further demonstrate their findings, a glass artist created a design inspired by the Lycurgus Cup using the replica dichroic glass. However, experts continue to debate whether Roman artisans intentionally crafted the color-changing effect or if it was an unintended consequence of using gold in the glass-making process. --- Source: [Live Science](https://www.livescience.com/archaeology/romans/lycurgus-cup-a-roman-glass-goblet-made-with-ancient-color-changing-nanotechnology) Published by News Central Site: https://newscentral.site/the-lycurgus-cup-changes-color-depending-on-lighting/