Not only a tongue twister, this colour changing chalice left scientists in knots as they struggled for decades to understand how it worked. Known as the Lycurgus Cup, it is both the only figural example of a type of vessel known as a ‘cage-cup’ and the only complete Roman glass object made from dichroic glass.
What is so fascinating about this chalice is that is changes colour depending if light is shone from the front or back. This colourful secret intrigued scientists and it wasn’t until 1990 they attributed this colour change to nanotechnology.
The Roman artisans “impregnated the glass with particles of silver and gold, ground down until they were as small as 50 nanometers in diameter, less than one-thousandth the size of a grain of table salt.” When light hits the metal nanoparticles, the electrons in the metal are excited in ways that alter the colour depending on the observer’s position.
I stumbled upon this beautiful chalice in a recent Smithsonian Magazine article as it seems scientists are tamping into this 1,600-year-old “technology” to create “supersensitive new technology that might help diagnose human disease or pinpoint biohazards at security checkpoints”.
If you’re like me and want to see the real thing you need to get yourself down to the British Museum.