Emerald has been one of the most sought after gems since antiquity. The mesmerizing green color of emerald is unique in gem world.
Emerald is a very rare gem. High quality and untreated emeralds are extremely expensive and valuable.
Emerald belongs to beryl group of gem stones and wonderful green color of emerald is because of presence of chromium and vanadium in its composition. Emerald is crystalline aluminum and beryllium silicate with traces of chromium and vanadium.
Emeralds exhibit excellent hardness of 7.5 to 8 on Mohs scale. Emerald is a very brittle stone in spite of its great hardness and should be handled accordingly and severe blows should be avoided.
Emeralds are often included and feather inclusions can be seen readily most of the time with naked eye. Surface reaching feather inclusions are the reason most emerald have fractures on surface.
Emeralds are nearly always treated with oil (oil treatment) and this kind of treatment is a very common practice in gem industry to improve clarity and color of an emeralds. Untreated emeralds of great color, clarity and carat weight cost a fortune.