1,600-year-old Roman goblet glows red because of silver and gold particles in the glass

A Roman goblet could be an 1,600-year-old example of nanotechnology, according to experts.

The mysterious Lycurgus Cup is made of dichroic glass and appears green when lit from the front and turns bright red when a light is shone on it from behind.

The Daily Mail reports that the chalice, which is on display at The British Museum, London, uses similar techniques to 'modern' nanotechnology - the manipulation of materials on an atomic and molecular scale - which scientists believe could be used for everything from diagnosing diseases to identifying bioharzards at airports.
 

Scientists only solved the mystery of the colour-changing chalice in 1990, after being baffled by its behaviour for decades, Smithsonian Magazine reported.

After putting broken fragments of glass under a microscope, scientists found the Romans had impregnated it with particles of sliver and gold, which they ground down to tiny proportions - around 50 nanometres in diameter - a thousand times smaller than a grain of salt.
 

The precise amount of metals has lead experts to hail the Romans as 'nanotechnology pioneers' who really knew what they were doing.

Archaeologist Ian Freestone, of University College London, who researched the cup and its unusual optical properties, called its construction an 'amazing feat'.

The cup appears to change color as when light hits it as the flecks of metals' electrons vibrate in ways that seem to change the color, depending on where the observer is looking at it.
 

The chalice was used to hold drink on special occasions and experts believe that when it was filled, the behavior of the vibrating electrons changed, as well as its color.

Gang Logan Liu, an engineer and nanotechnology expert at the University of Illinois at Urbana-Champaign told the publication: 'The Romans knew how to make and use nano-particles for beautiful art.'

Of course scientists could not investigate the effects of the one-of-a-kind cup by filling it with liquid.

Instead, they reportedly imprinted billions of little wells onto a piece of plastic the size of a postage stamp and sprayed them with gold
and silver nano-particles to essentially re-create the special configuration of the cup.

The scientists then poured different liquids into the wells to note the effect they had.
When they filled a well with water it turned the surface light blue, while pouring oil inside turned it bright red.

While the experiment may help archaeologists understand how the chalice works, it could also aid scientists in developing devices to detect pathogens in saliva or urine samples, or by identifying liquids terrorists might try and smuggle onto airplanes.