The Lycurgus Cup looks like two different objects depending on where the light comes from: opaque green when illuminated from the front, glowing red when light passes through it. Now a Sheffield glass technician and a sculptor have made a new artwork that repeats the Roman vessel’s extraordinary transformation.
The difficult part was not simply putting gold into glass. Technician Lisa Hollands had to make tiny amounts of gold and silver take the right form inside it, experimenting with furnaces, ingredients, oxygen levels and even sugar. The result was glass that could be worked into a contemporary sculpture, rather than a color-changing effect confined to an explanation on a museum label.
The light moves. The glass stays the same.
The fourth-century original is held by the British Museum. Its two colors are a property called dichroism: reflected light and transmitted light produce different appearances. The Corning Museum of Glass’s explanation distinguishes this from iridescence, weathered surfaces and glass that changes appearance under different kinds of lamps.
That distinction is worth keeping in mind when looking at photographs. A green image and a red image do not show an ancient object before and after restoration. Nor does the cup need a fresh coat of dye. Change the route the light takes, and the same material gives a different answer. The lighting is part of the demonstration, not evidence that somebody swapped the artifact.
Corning researcher Robert Brill attributes the Roman glasses’ behavior to light scattering involving minute quantities of gold and silver. Modern glassmakers can also produce color-shifting effects with coatings, but that is not the same construction as metal particles embedded within the ancient glass.
A recipe is more than a list of ingredients
According to Sheffield’s October 26 report, Hollands worked with Roman-glass specialist Caroline Jackson to develop a base glass from modern materials that would approximate ancient ingredients. Once the team could make the effect, artist Elliot Walker, winner of the second season of Blown Away, took on the challenge of turning it into a finished piece.
Earlier analysis helps explain why the furnace trials mattered. A 2007 study by researchers at Cardiff and the British Museum describes metal particles roughly 50–100 nanometers across in the original cup. It also explains that composition, heating time, temperature and chemical conditions influence the resulting color. Knowing which metals are present therefore does not hand a glassmaker a complete manufacturing recipe.
The same study describes how fragments found beneath a later-added base allowed researchers to examine the ancient material. The cup itself had become a record of a vanished workshop: not written instructions, but chemical and microscopic clues that survived inside the finished object.
The sculpture changes the form, not the central trick
Walker’s new work combines the Lycurgus story with the pose of the Farnese Atlas, replacing the globe with a cup. The official exhibition listing identifies the collaboration with Hollands and Professor Russell Hand and promises a lighting arrangement that demonstrates the transformation.
The University of Sheffield’s film below concerns the modern project. It should not be mistaken for footage of a newly discovered Roman cup or a reconstruction of an ancient workshop.
The original was already doing something remarkable
The Roman vessel has another feat hiding in plain sight. As Corning describes its construction, the outer decoration was cut and ground away from a glass blank until a delicate cage of figures remained suspended around the bowl. The visual drama comes from both material and workmanship: the transparent wall changes color behind the sculpted figures.
The British Museum identifies those scenes as the death of King Lycurgus. Its gallery account describes a myth in which a threatened nymph becomes a vine and traps the king. This is a drinking vessel with a supernatural revenge story worked into its glass, not merely an ancient laboratory curiosity.
What has been recovered—and what has not
The modern achievement needs one important qualification. Sheffield presents its work as a reproduction in quantity, but the underlying optical effect was understood before this announcement. Corning’s account explicitly describes earlier laboratory reproductions of Roman dichroic color combinations. Calling this the first time anyone has reproduced the phenomenon would erase that work.
Nor does a successful modern recipe establish exactly what the Roman makers knew or how they controlled every batch. What it does provide is tangible: another artist can now shape glass with the old vessel’s startling behavior. The new sculpture is due at Sheffield’s Millennium Gallery from November 6–15, before moving to the university’s Turner Museum of Glass. The ancient cup remains extraordinary; now its most surprising feature has a new object in which to perform.
Featured photograph: the original Lycurgus Cup at the British Museum, photographed by Chappsnet via Wikimedia Commons, CC BY 4.0. Commons’ resized photograph is used without cropping or other alteration; it does not depict the new sculpture.
