Emerald is known as the birthstone of May. The person who is the owner of emerald is believed to bestow with the power of foresight, youth and good fortune. The emerald is a rebirth symbol. Smaragdus is a word from which the word emerald has been derived. The meaning of smaragdus is green in Greek. In early 330 B.C emerald was mined in Egypt. Now emeralds are mostly mined in Zambia, Brazil, Colombia and Afghanistan. High-quality emeralds are available in a limited way and for this reason treatments are regularly performed to improve the quality of emerald. If judged by weight emerald is the most valuable stone in the world.
The green colour of the emerald occurs mainly due to its absorption of some particular wavelength of light which is known as body colour. The most exquisite emerald stones are found in Columbia. The colour of the Colombian emerald is bright grass- green colour with a nudge of blue. Recently emerald has been found in North Carolina. Quality emerald can be found in here if the mine continues to supply emerald. Many jewellers avoid washing emeralds with ultra-sonic devices as it can discard the coating.
The gradation of the emerald is being done by its shape, colour and clarity. There are different grades such as good, commercial, extra fine and fine. The qualities range is being represented by every grade. The green colour of the emerald is produced by the element of chromium present in the stone. The garden or jardin of the emerald is created by the stone inclusions. Hexagonal structure is the crystal structure of the emerald. Emerald comes from the Beryl family. An emerald which is fine in quality is more valuable than a diamond of high-quality of the same weight. On the Mohs scale the hardness of emerald ranges from 7.5 to eight.