The 21st century's three Rs -- Reduce, Reuse, Recycle -- were all the rage in Britain during the last century of Roman rule, a compositional analysis of ancient Roman glass tableware has revealed.
According to the study, published in the Journal of Archaeological Science, large quantities of glass were recycled in Britain during the 3rd and 4th centuries A.D.
The reason wasn’t exactly a desire to go green, but a shortage of raw glass in the northern regions of the Roman Empire during the last centuries of Roman rule.
“It appears much of the glass reaching Britain in the late Roman period was manufactured from recycled material,” Caroline Jackson, at the archaeology department of the University of Sheffield, U.K., told Discovery News.
Believed to have originated in Mesopotamia around 2500 B.C., the art of glass-making spread to Egypt, with the most significant technological revolution -- glass blowing employing a tube -- occurring in the 1st century B.C. in the area of Syria and Palestine.
The Romans exploited the technique, and glass-making spread throughout the empire, with glass becoming a common household material.
Made out of sand, glass takes on the color of the chemical elements present in raw material. For example, sand containing iron produces blue-green glass, while iron and sulfur elements make a brownish glass.
Skilled Roman craftsmen were able to control glass color through a careful selection of the raw materials, and produced colorless glass by adding a decolorizer, an element which oxidizes the chemicals in the sand to remove the color.
“In the Roman period, this element would have been antimony or manganese,” said Jackson.
Resembling crystal, colorless glass was much valued. According to the Roman author, Pliny, the emperor Nero (37-68 A.D.) gave 6,000 sestertia (roughly $250,000) for two clear glass cups of ordinary size, with handles.
A highly developed and successful industry, Roman glass-making still holds some mystery. It is unknown where colorless glass was produced, and scholars still debate how the glass industry was organized.