This is the Lycurgus Cup, a glass vessel dating back to Roman Empire of the fourth century. It is made of intricately-carved glass with a strange property. Under normal light, it appears to be an opaque jade green. But lit from the back, it glows a translucent red! This is dichroic glass, and displays different colors because of nanoparticles of gold and silver embedded in the glass. It is the only intact example of such glass, although a few shards of broken glass have been identified as dichroic. This property was only understood more than a thousand years later when scientists recreated it using nanotechnology. However, experts believe that the colloidal gold and silver were introduced into the molten glass by accident, since nanoparticles are too small to be seen by the naked eye.
The real miracle, as I see it, is that a glass cup from the fourth century has survived fully intact instead of being smashed to smithereens, which is what's happened to most of the glassware I've owned. The Lycurgus Cup is indeed cracked, and held together by its metal rim around the top. The mythology depicted in its carving tells a story in itself, as detailed at the DeBrief. -via Strange Company
(Image credit: Chappsnet)
