"Emerald Mountain" and its surroundings were the only emerald
mining areas within the borders of the Roman Empire. The Habach Valley
in Austria, another place within the Roman territory with emerald-containing
rocks, has produced no evidence of mining in the Roman period. The
earliest mention of this European emerald valley dates, in fact, from
Analyses of the few surviving pieces of Roman jewelry with gemstones
suggests that Rome also imported some emeralds from India, probably
through the port of Berenike. Pliny described the use by Emperor Nero
of an emerald looking glass while watching gladiatorial fights. Although
Pliny's identification of the gemstone used in this "looking glass"
was probably incorrect, he was the first one to suggest that emerald
was a form of beryl. The scientific proof for this assumption came
only in the 19th century.