Since antiquity, emerald has been one of the most highly valuated gemstones: the first known mines were those of Cleopatra in ancient Egypt. Two thousand years ago Pliny wrote, "Emerald-green is the most beautiful green of all. " Leading researchers offer insight into many of the aspects of the world of emerald. What is an emerald? How does an emerald form? Where is emerald found? Worldwide localities Where are the richest deposits? Today's market sources Is it possible to determine the origin of an emerald? What seperates green beryl from emerald? How is emerald created in the lab and how can it be recognized?