The Emerald is a silicate of aluminum and beryllium. Emerald is a gemstone of green color belonging to the family of beryl gems. It is rare as it is very difficult to find a flawless emerald. Most Emeralds are defective, having a feather-like crack and inclusions. To find an emerald of rich green color, perfectly transparent, with a velvety reflection and high specific gravity is difficult. Astrology suggests wearing an Emerald helps you get rid of negative impacts created by a weaker Mercury in your horoscope. According to classical Hindu literature, Emerald represents a small yet powerful planet, Mercury (Budh) bears a strong influence. It is one of the great five gems, known in Indian jargon as ``Pancha Ratna``.