Dating back to the years when Cleopatra ruled Egypt, emeralds have adorned the crowns of royalty for centuries now. Know as the “gem of good luck”, emeralds are a member of the beryl family of gemstones; a popular family for jewelry due to its extreme brilliance and hardness.
When purchasing emeralds, the most important quality to look for is color followed by cut and clarity. When judging a stone for color, one would want to make sure that it has the darkest color possible. To get an accurate reading on the color, one should always look at the color along the edge of the stone and not straight down the middle. Other color concepts to be aware of when buying emeralds or any gemstones are color zones and color bands. Color zones are areas of the gemstone that have a lighter or darker color then the general color of the stone. Color bands are streaks of dark or light colors that run through the gemstone.
The next important concept when buying a good quality emerald is the cut of the stone. Cut is important because it brings out the color of an emerald and the more color that it displays, the more beauty and value the emerald will have. There are three important factors when it comes to cut: symmetry, polish, and windowing. Symmetry is the easiest when determining the quality of emerald because one should observe along the outline of the gemstone to see if it is of symmetrical shape. One should also study the emerald while rotating it three hundred and sixty degrees to see if the facet junctions are lined up. Next, under an overhead light, one should look at the surface of the emerald. The presence of little lines appearing like scuff marks signifies wheel marks from the polishing phase. The presence of these marks takes away from the beauty and value of the stone. The last is windowing of the gemstone. Windowing simply means that one can look through the top of a gemstone and see right through to the bottom.
The final factor when buying an emerald is clarity. Clarity is always the last thing to look at when evaluating whether a gemstone is worth buying. Impurities in gemstones cause color and usually with impurities you will have inclusions. Emeralds are a category 3 gemstone; meaning that these gemstones will always have inclusions to some degree. In fact, if emeralds did not have any inclusions in them then you would have either an extremely rare emerald or a synthetic. When observing the clarity inside an emerald, one should use a 10x loupe and a flashlight for dark field illumination which is transmitted light from either the side or behind the gemstone. When observing the surface of an emerald for any imperfections one should use a 10x loupe and an overhead light.
Brazilian and Colombian are two different types of emeralds available in today’s market. The difference between these two emeralds is their value. Colombian emeralds are priced higher then Brazilian due to their darker color. One can tell whether they have a Brazilian or Colombian emerald because under a 10x loupe, one will observe mica inclusions found only in the Brazilian type.
Hydrothermal and Chatham are the two types of synthetic emeralds that are available for purchase and can easily be separated from natural emeralds. Hydrothermal emeralds are fairly clean of inclusions and have color bands that are parallel to each other. Chatham emeralds have flux fingerprints which are inclusions that resemble its characteristic; a fingerprint. When it comes to treatments on emeralds, oiling is the only process that is used. Oiling is used to preventing foreign objects from getting into the gemstone. It is also used for making the fractures on the surface less noticeable; however one should be aware that placing these fractured, but treated emeralds in jewelry can still cause the gemstone to crack.
Emeralds are a beautiful and highly durable gemstone that have great potential to be a “gem of good luck” if it is a high quality emerald purchased at a good price.