Emeralds are highly valued, deep green gems, deriving their color from chromium. They are the traditional May birthstone, though those born in May might require deep pockets to obtain a good quality emerald. The nature of their formation leads to a greater number of flaws in emeralds than in some other gems. Therefore, a relatively unflawed gem is rare and expensive.
Emeralds can be found throughout the Middle East, but are now primarily mined in Columbia. Middle Eastern cultures valued the gems greatly, and representations of jewelry containing emeralds predate the Common Era. Cleopatra was said to have thought emeralds were the finest of all gems. The Maharajahs of India treasured the emerald as well, and old treasure collections of past Indian rule are filled with these marvelous green stones.
The Mogul Emerald is one of the largest known stones, over 200 carats in size. This gem is currently owned by an unidentified buyer, who purchased it during a 2001 auction at Christie’s for over 2,000,000 US dollars (USD). The largest known stone was found in Columbia, and is extremely impressive at over 600 carats. It can be viewed at the Museum of Natural History in New York City.
Though emeralds have a hardness of 7.5 on the Mohs Scale, inclusions in the stones can cause easy breakage. For this reason, commercial emeralds are often coated in resin to avoid damage to the stone. All emeralds have some flaws because they form in three stages. Flaws are referred to as jardins, French for garden, suggesting that flaws naturally blossom from formation processes.
Small, greatly flawed emerald chips are generally inexpensive adornments in jewelry. Large numbers of flaws affect luminosity of the stone, and small chips may look more like jade than a clear gem. Larger emeralds with fewer jardins are indeed rare, and can therefore be very costly. A two-carat stone of the highest quality can cost as much as 15,000 USD.
Emerald quality can be assessed as highest, high, jewelry, commercial, and low. High quality two-carat stones range from 3,000 to over 4,000 USD. Jewelry quality two-carat stones are slightly over 2,000 USD. The lowest quality two-carat stones may be purchased for less than 200 USD.
When choosing emeralds for jewelry, sometimes smaller gems are better choices because a higher degree of quality may be obtained for a lower price. A small stone with greater clarity will show up more than a larger stone riddled with flaws. Even small stones, though, can be expensive as compared to other gems.
Clarity of emeralds is also scaled, from i1 to i9. Emeralds with an i1 rating are very rare, as they contain the least inclusions. Conversely, i9 emeralds can be found in abundance, but have so many jardins that they appear muddy.
Any emeralds rated i4 or lower have flaws only visible through magnification. However, many are happy with jewels with a higher than i4 rating, because one naturally expects jardins. As such, emeralds echo life in being less than perfect.