Emerald is one of the most well-known and desired colored gems known to mankind. There is evidence of emeralds being mined and used in jewelry going back to over 3,500 years before present. It is a variety of the gem beryl, colored green by minute traces of chromium, vanadium or both. While emerald has a hardness of 7.5-8 on the Mohs scale, it is typically very included, which limits its toughness. To increase the clarity and durability of the gems, nearly all emeralds are filled with either clear resins or oils. This means that special care should be taken when cleaning emeralds.
There are no named varieties or species of Emerald.
Where is it found
Emerald is found in a number of localities in the world. However, the largest deposits mined today are in Colombia and Zambia. The Colombian emeralds are widely regarded as the finest in the world due to their high chromium content and relatively high clarity for emerald. In the United States there are minor deposits of emerald in North Carolina.
Untreated emerald is extremely rare and valuable. Because emeralds are almost always filled with cracks and fissures when they come out of the ground, they are typically filled with resins or oils to improve the clarity and stability of the stones. These resins should be colorless, but occasionally colored resins are used to falsely enhance the color of the gems. While oils like cedar oil were commonly used in the past, in recent decades this has largely been replaced by specialized resins that are more durable, and closely match the refractive index of the emerald, giving the gem a better overall appearance. Even though treatment is common in emerald, it should still *always* be disclosed to the buyer.
Use in jewelry
Very few jewels are as popular in jewelry as emerald. While relatively hard, the internal fissures reduce the toughness of the gem. As a result, it should be treated with care, particularly when cleaning it. That said, it’s hard enough to be used in any type of jewelry, and is particularly popular in rings.