This is the Cup of Lycurgus, which was made in Rome, and probably in Alexandria itself about 1600 years ago
And it is capable of changing color. If the artifact is illuminated by daylight from the front, it has a greenish tint, if illuminated from behind, it turns red.
The archaeologists' dating is based solely on the fact that the first to excel in glass were the Romans. There is no further evidence that it was created in the
4th century AD. In the composition of 1 million particles of glass by unknown creators were added
330 nano-particles of silver and only 40 gold. At the same time, the size of these particles was only
50 nanometers. Thanks to this there is a change in color at different angles of illumination.
An open question: how could the Romans at the dawn of our era obtain nano-particles of the right size?
