The Emerald is a rich green stone that can be more valuable than a diamond of the same size. Emeralds are part of the beryl family of precious stones. They have a hardness of 8 and a sp.gr of 2.7 to 2.9. The emerald is considered a gem, or a mineral that is desired for its beauty and durability. A large number of minerals are considered gems. Emeralds and beautiful stones like it have their value determined by four different factors: the beauty of the stone, how rare the stone is, the stone"s hardness and toughness, and the way the stone has been cut or polished. The emerald itself is used mostly for jewelry and must be cut into a certain shape. .

             The history of the emerald goes back to ancient times when the gem was considered to have healing powers of the eye. Emeralds in ancient times were mostly mined in Egypt, where they were greatly valued and only members of the upper class owned them. Today the emerald is mined in several different countries, but the main supplier is the South American country of Columbia. The Inca mined the Columbian emerald in ancient times before the Spanish arrived. The world"s largest emerald however was mined in the Ural Mountains of Russia. The emerald weighed six pounds and is now on display in the Leningrad museum. .

             The emerald is a type of beryl, or a valuable gem material that is also a mineral. Beryl is chemically consisted of aluminum beryllium silicate. The chemical formula for beryl (and the emerald) is Be3Al2(SlO 3)6. The pure type of beryl is colorless and clear. Other stones that are also forms of beryl include: aquamarine, morganite, golden beryl, and rose beryl. Beryl usually forms in a hexagonal shape, which gives the stone eight different sides. Beryl can come in several different colors, but emeralds usually only come in green. The emerald gets its greenish color from the small amounts chronic oxide inside it. Emeralds do not have as such large crystals as pure beryl, and can be split into thin slices like a loaf of bread, also making it different from beryl.