emerald is a variety of beryl, a mineral that grows with six sides and up to a foot in length. Emerald color can range from light green (though there is some argument whether these very light beryls are truly emeralds) to a deep, rich green. Emeralds are also like aquamarine in that the way the color is presents itself in jewelry depends on a good cut by a skilled gemologist.
The deeper or more green an emerald, the more valuable it is. The rarest emerald gemstones will appear to be an intense green-blue color.
Emerald gems are found all over the world, including Colombia, Brazil, Afghanistan and Zambia. The availability of high-quality emerald is limited; consequently, treatments to improve clarity are performed regularly.