More valuable than even diamonds, fine-quality emeralds of significant size are among the world’s most rare gems. Their incomparable dark green color is produced only under extremely rare conditions, and because these conditions also result in tiny cracks and cavities in the stone, inclusions are allowed in top-quality emeralds. Unlike most gemstones, inclusions don’t generally diminish the value of an emerald. In fact, the “garden”, as it is called, is considered a sign of the natural history of the gemstone.
The first known emerald mines were in Egypt next to the Red Sea, and Cleopatra was known to have a passion for emerald, and used it in her royal adornments. Early lapidaries relied on emeralds to soothe their eyes when cutting gems. Even today, the color green is known to relieve stress and eye strain. Emerald is a rare and valuable gemstone and, as such, it has provided the incentive for developing synthetic emeralds.
Both hydrothermal and flux-growth synthetics have been produced, and a method has been developed for producing an emerald overgrowth on colorless beryl. Emerald is a variety of the mineral beryl and derives its color from trace amounts of chromium and sometimes iron. It is highly prized as a gemstone and by weight it is the most valuable gemstone in the world.