Emerald, whose etymology most probably comes from the Greek word smaragdos (or smaragdus for the Romans, is the most famous variety of beryl, an alumino-silicate of beryllium, known for the numerous gems to which it gives origin. According to scientist John Sinkakas, the word beryl itself relates to the city of Belur, an old trading center in India. Successive derivation of the word gave birth to the Greek word beryllus, the Roman berrullus or beryllus and our modern beryl.
All gemological varieties of beryl have the same general formula and the same structure. They stem from the presence of trace elements inside the mineral, whose composition and structure remain basically unaltered. On the basis of their color, one can distinguish colorless beryl as goshenite, blue beryl as aquamarine, yellow asheliodore, pink as morganite and red as bixbite. The marvelous green color of emerald, due to the presence of Cr, V, and Fe in its structure, has attracted peoples' attention since remote times.