Scientists recreate Lycurgus Cup's colour-changing effect in new glass sculpture

University of Sheffield team revives ancient Roman technique using gold and silver nanoparticles

By LineZotpaper AI staff

Published27 October 2026

Updated27 October 2026

Read Time2 min

Sources2 outlets

Illustration: Scientists recreate Lycurgus Cup's colour-changing effect in new glass sculpture

University of Sheffield scientists have produced a contemporary glass sculpture that recreates the famous colour-changing effect of the 4th-century Lycurgus Cup, using the same ancient Roman recipe that relies on gold and silver nanoparticles.

The Lycurgus Cup, dating to around 400 CE, is made of dichroic glass. It appears green when lit from the front and deep red when lit from behind. The cup is one of only about 40 surviving cage cups and is considered among the seven wonders of glassmaking.

For centuries, the cause of its unusual colour shifts was a mystery. In 2007, scientists determined that the effect stems from nanoparticles created when Roman artisans added finely ground gold and silver to the glass. The nanoparticles alter how electrons in the glass vibrate in response to light, shifting the colour with the observer's vantage point.

The recently created sculpture was made by Sheffield researchers who recreated the original recipe. The process mirrors how ancient stained glass was made: Roman glassmakers added salt containing gold atoms to melted sand. During melting, those atoms aggregate into nanoparticles, producing the colours. The phenomenon is similar to the iridescence seen in butterfly wings and opals, caused by the lattice-like structure of photonic crystals.

The work demonstrates how modern science can revive and illuminate ancient technological achievements.

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Analysis

Why This Matters

The recreation validates modern understanding of ancient Roman nanotechnology.
May inspire new applications of dichroic glass in art and technology.
Shows the value of investigating historical artifacts with modern scientific tools.

Background

The Lycurgus Cup is a Roman cage cup from the 4th century CE, named for its depiction of King Lycurgus of Thrace. It is made of dichroic glass, a rare material that changes colour with the angle of light. The cup's colour mystery persisted until 2007, when nanoparticle analysis revealed the presence of gold and silver colloids. This discovery connected ancient Roman glassmaking to modern nanoparticle science.

What to Watch

Whether the recreation technique can be adapted for industrial or artistic purposes.
Potential for similar recreations of other ancient dichroic glass artifacts.

Sources

Sculpture recreates odd optical effects of famed Lycurgus Cup · Ars Technica
Sculpture recreates odd optical effects of famed Lycurgus Cup · Ars Technica

Checked

12 claims in this story checked against 1 source: 11 supported.

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SupportedScientists recreated the Lycurgus Cup’s colour-changing effect in a new glass sculpture.Science - Ars Technica: “University of Sheffield scientists have recreated the original recipe to produce a contemporary glass sculpture with the same optical effect.”
SupportedA University of Sheffield team revived an ancient Roman technique using gold and silver nanoparticles.Science - Ars Technica: “University of Sheffield scientists have recreated the original recipe to produce a contemporary glass sculpture with the same optical effect.”
SupportedThe Sheffield researchers produced a contemporary glass sculpture using the original recipe.Science - Ars Technica: “University of Sheffield scientists have recreated the original recipe to produce a contemporary glass sculpture with the same optical effect.”
Not in the sourcesThe sculpture was recently created.Science - Ars Technica: “University of Sheffield scientists have recreated the original recipe to produce a contemporary glass sculpture with the same optical effect.”
SupportedThe Lycurgus Cup dates to around 400 CE and is made of dichroic glass.Science - Ars Technica: “Dating back to around 400 CE and made of dichroic glass, the Lycurgus Cup is notable for exhibiting different colors depending on the light.”
SupportedThe cup appears green when lit from the front and deep red when lit from behind.Science - Ars Technica: “Light it from the front, and the cup looks green; light it from behind, and the color changes to a deep red.”
SupportedAbout 40 glass cage cups have survived, including the Lycurgus Cup.Science - Ars Technica: “The cup is considered one of the seven glass wonders of the world, one of just 40 glass cage cups that survived.”
SupportedThe Lycurgus Cup is considered among the seven wonders of glassmaking.Science - Ars Technica: “The cup is considered one of the seven glass wonders of the world, one of just 40 glass cage cups that survived.”
SupportedThe cause of the cup’s colour shifts remained a mystery until 2007, when scientists found that nanoparticles in the glass caused them; the particles resulted from Roman artisans adding finely ground gold and silver.Science - Ars Technica: “Exactly why the unusual color effects of the Lycurgus Cup occurred was a mystery until 2007, when a team of scientists discovered the color shifts were due to the presence of nanoparticles in the glass—the result of Roman artisans adding finely ground gold and silver into the mix.”
SupportedThe nanoparticles change how electrons in the glass respond to light, shifting the colour with the observer’s vantage point.Science - Ars Technica: “Those nanoparticles change how the electrons in the cup vibrate in response to light so that the color one sees shifts with the observer’s vantage point.”
SupportedRoman glassmakers added salt containing gold atoms to melted sand; as the glass melted, the atoms formed nanoparticles that produced the colours, and the process is how stained glass is made.Science - Ars Technica: “The Romans added salt when they melted the silicon (sand) to make the glass, and those salts contained gold atoms. In the melting process, those atoms aggregate and produce nanoparticles, which in turn produce the colors. It’s how any stained glass is made.”
SupportedThe phenomenon is similar to the iridescence of butterfly wings and opals, which comes from the lattice-like structure of photonic crystals.Science - Ars Technica: “It’s also similar to how the precise lattice-like structure of photonic crystals produces iridescent colors in nature, like the wings of butterflies, or opals.”