Emerald, the green variety of Beryl, is the most famous and valuable green gemstone. Its beautiful green colour, combined with durability and rarity, make it one of the most expensive gemstones.

Emeralds are fascinating gemstones. They have the most intense and most radiant green that can possibly be imagined: emerald green. The lively luminosity of its colour makes the emerald unique. Deep green is the most desired colour in Emeralds. In general the paler the colour of an Emerald, the lesser its value. Very pale stones are not called Emeralds but rather "Green Beryl".

Though Colombian Emeralds have traditionally been the highest quality Emeralds with the finest green colour, a new source of Emerald from the African country of Zambia has been producing deep green Emeralds with fewer flaws. However, really good quality is fairly rare, with inclusions often marring the evenness of the colour. Emeralds are notorious for their flaws. Flawless stones are very uncommon, and are noted for their great value. Some actually prefer Emeralds with minute flaws over flawless Emeralds, as this proves authenticity.