Emerald is one of the most popular gemstones, and is a variety of Beryl. It is always green in apperance, or at least it must to be considered a emerald. Although other hues (or colours) are accepted, the majority colour of an emerald must be green. They are a 7.5 rank on the moh scale, which still makes them relatively durable and certainly they are not weak. However, their weakness when compared to moissanite and diamond, and ruby and sapphire makes them fairly useless for industrial use. Furthermore, as a large majorites of emeralds are included, there resistance to breakage is not good.
Because of the large amount of inclusions common in emeralds they are not graded for clarity under magnification, instead a trained eye checks if there are any inclusions. In this way an emerald can be considered flawless if there are no inclusions visible without magnification, even though it is almost certain that the emerald will have many inclusions. Because of this clarity is not normally given too much weight when deciding to buy an emerald or not, although it is certainly important, colour is generally deemed more important.
Emeralds are also frequently treated to enhance appearance with heat-treating to enhance colour, while an oil finish appears to improve clarity and is not frowned upon within the emerald industry as it is for other gemstones. Furthermore, some emeralds are filled with lead glass to further decrease the impact and appearance of inclusions, but this practice is normally frowned upon. Emeralds have found many uses in the jewelry world, whether it be as or engagement rings, they are beautiful alternative that is sure to draw attention.