Buying an emerald is much less technical than buying a diamond. Diamond's are treasured for their brilliance while emeralds are loved for their color.
As you probably know already from other articles on our Essilux website, we encourage readers to learn about the importance of the 4Cs when purchasing diamonds. Though we use the same 4Cs for emeralds, we give greater or lesser weight to each one, according to its particular significance when assessing emeralds. Let's take a look at each one, in order of importance:
Without a question, color is by far the most meaningful of the 4Cs. What captivates you right away when you see an emerald is undoubtedly its color - either a vibrant, passionate color or a dull, limp color or possibly somewhere in between.
The human eye can see more shades of green than any other color. This makes color the most important characteristic of an emerald as hue and intensity can vary greatly. When it comes to color, the most desirable hue range is from bluish-green to yellowish-green with medium to vivid saturation. The green color of emeralds is determined by the impurities of chromium and/or vanadium, depending on the mine, this means that emeralds from different parts of Colombia, as well as the world, have different shades of color. By looking at color alone, an expert can figure out the location of origin.
Just as we explain in our guide about fancy color diamonds, color is really broken up into three categories: hue, tone, and saturation.
Hue describes the emerald's basic color, The most valuable and beautiful emeralds exhibit an "intense bluish" hue in addition to their basic green color.
Hue means the type of green color the emerald has, for example, yellowish green or bluish green. Most emeralds on the market today are Colombian, and most Colombian emeralds are bluish green.
Tone is how dark or light a color appears. It represents the depth of color, ranging from colorless to black. Medium dark green and deep intense are the best one tones. However a dark green tone does not mean it will be of the highest quality, since it may not show brilliance or be crystallinity.
Most people mistakenly assume that they should choose emeralds of medium to very dark tone because they believe that the darker the tone, the better. But this is not necessarily true, what is just as important to the look of the emerald is its saturation.
This is what gives the color its intensity and strength. Saturation can range from light to exceptional vivid. So if, for example, a medium dark stone has a boring, dull saturation, you probably won't get too excited about it.
But if you find a light green emerald sparkling with vivid saturation, your eyes are much more likely to be drawn to it, and you may like the lighter tone, as well.
The bottom line to remember here is that the darker tone and higher saturation grades will usually result in a higher price tag, but that doesn't mean that you might not find an emerald breathtakingly beautiful slightly below this range.
Often customers are shocked to find out that the emerald they fall in love with is actually one with light tone but with good saturation. They might say something like, "I've never seen an emerald with this kind of intense green color before!"
Of course, since color is by far the most important factor when buying emeralds, it should go without saying that you need to be able to see a high quality photo of the stone before even considering purchasing it online.
This is why we strongly recommend buying emeralds only from reputable jewellers. Another important thing to remember about emeralds is that they are rarely sold with a reliable certificate.
With emeralds (as opposed to diamonds) this isn't a deal breaker. As long as you have a guarantee that the emerald is natural, all that really matters is how the stone looks to you.
Don't be concerned with "investment value." If the hue, tone, and saturation of an emerald speak to your sense of beauty, that is all that is relevant.
Emeralds are gemstones. Therefore, they can be graded by the preferred grading system for all gemstones: Natural AAA, AA, or A.
Natural AAA: This is the highest quality. It represents are the top 10% of gemstones. Natural AAA emeralds are rich green, moderately to slightly included, and they exhibit very high brilliance.
Natural AA: This is the second-best category for gemstones. Natural AA gemstones account for 20-30% of all gemstones. Emeralds in this category are medium green and may include moderate inclusions.
Natural A: This category accounts for 50 to 75% of all gemstones. Natural A emeralds are dark green, heavily included, and opaque. They are still good, but they are considered to be of a lower quality compared to the two categories above.
Apart from Natural AAA, AA, and A, there's also a category called Heirloom/Rare Emerald. This is the highest quality, even better than AAA. They are extremely rare and expensive.
As with diamonds, emeralds with better clarity fetch a higher price at market. But that's where the comparison ends. Whereas with diamonds there is a clear clarity grading scale, with emeralds there is not.
The other major difference is that we expect to see inclusions (imperfections that lower the clarity grade) in about 99% of emeralds. In fact, when you don't see inclusions, you need to be suspicious that the emerald is not natural.
The GIA classifies emeralds as "type III," which means they are almost always included. Emeralds belong to the beryl mineral family, and their inclusions result from bits of liquids, gas, and other minerals like chromium and vanadium.
These inclusions are known as "jardin,' the French word for garden since the inclusions may look like branches or plant roots, but they are also what cause the stone to be that gorgeous green color.
So don't worry, inclusions are a natural part of the character of emeralds. But you should also know that since emeralds are so heavily included, about 80-95% of the rough must be cut away to produce a gemstone, thus giving a smaller yield and a bigger price tag.
Even though you will find inclusions and fissures, you need to pay attention to what kind they are. Stay away from inclusions that look like bubbles, imperfections that look arranged in a specific order, and obviously big blotches.
Be sure that the stone's inclusions are deep under the surface, otherwise they can create fractures when set or worn. This point is especially important because emeralds are not as strong as diamonds and will chip more easily. And bottom line: make sure you see a magnified picture of the emerald to see its jardin before purchasing.
Various inclusions can form naturally within an emerald. Each inclusion has a different appearance and affects the value of the emerald in different ways. Inclusions can typically be seen with the naked eye and all inclusions can be seen with a 10x microscope.
Cavities & Chips
As with diamonds, the cut of the emerald refers to its faceting, shape, width and depth. Ideally, an emerald should be cut symmetrically with uniform facets that allow for paramount color and brilliance. If cut too deeply, the light will escape on the side and the emerald will look dark.
If too shallow, the emerald will not appear brilliant since the light will be lost at the bottom of the stone. The rectangular or square step cut called "emerald cut" is thought to maximize the shape of the rough. This is the most common cut, and hence why the name "emerald cut" stuck, even when applied to other gemstones.
Besides emerald cuts, there are round and oval cuts, but these are both more expensive and rare since so much more rough must be wasted to cut them. After these, there are pear cuts and cabochons (think of the rounded convex shape of a gem in a brooch), and much less likely are princess, brilliants, trilliants, and other fancy cuts.
Bigger is better, right? Well not necessarily. Carat weight obviously helps determine the price of the emerald, and a 4.00 carat stone will be more expensive than a 1.00 carat stone, all other factors being equal.
But carat weight plays a much larger role in the pricing of diamonds than it does with emeralds. With the latter, we are primarily interested in the color of the stone, then its clarity and cut, and only finally its carat weight.
Emerald experts agree that it's better to buy a smaller emerald with excellent color quality than a larger one with poor color quality. Beware that there will be a big price jump once you hit 1.00 carat since it takes, on average, the removal of five tons of dirt to find a gem quality emerald over 1.00 carat.
Most reputable jewellers offer consumers only the highest quality, authentic gemstones. Their colored gemstones undergo rigorous internal inspections by trained gemologists to ensure they meet stringent quality standards.
Due to their rarity and unique visual properties, nearly all colored gemstones sold at reputable jewellers, are enhanced using various techniques. Many of these techniques have been used for centuries. Colored gemstones that have not been enhanced are very rare and command extravagant prices.
While colorless and fancy color diamonds are not enhanced in any way, other than normal cutting and polishing. Black diamond fashion jewellery contains natural diamonds that have been treated to create the unique black color.
The vast majority of emeralds available on the market are treated to enhance their appearance. Such treatments help to improve their color and to decrease the visibility of their inclusions, as well as make them more durable. Due to the highly included nature of emeralds, it has become standard practice today to treat the stones with oils or resins to enhance clarity. Cedar oil is often used to improve emeralds' clarity, as well as other synthetic oils and polymers.
As mentioned, enhancement techniques are used to improve the look of the color and clarity of the emerald. Oftentimes, natural emerald do have clarity imperfections that can be permanently improved with these treatments. Unlike sapphires and rubies, emeralds are not treated with heat. It is rare to find an emerald that does not have color or clarity imperfections. 99% of emeralds are oil treated to enhance appearance.
Oil Treatment: Since emeralds are sensitive to high temperatures, they are usually treated with oils. Jewellers traditionally used cedarwood oil because it is both colorless and has a refractive index close to emeralds. Emerald jewellers generally accept the use of oil, but do not look favorably upon green tinted oil. During an oil treatment, the gem is gently heated to open its pores and filled with oil under low levels of pressure. The oil fills up tiny fissures, which helps to fade inclusions and enhance the color.
Resin or Polymer: Another type of treatment is opticon filler which is a plastic polymer resin. It is injected into gems under a vacuum. Opticon filler withstands wear and tear better and gives the stone more stability, improving its color. However, resins can yellow and disintegrate with time. Treated or filled with resin or polymer are treated in a similar fashion as those with oil. These treatments fill the emerald with a foreign substance that can detract from the overall look and value of the gem.
Wax Treatment: Another less common treatment involves heating wax and using it to fill the cracks within an emerald. However, this treatment is less desirable as it can leave behind a yellowish or gritty look when looked at under a microscope.
Although the jewellery industry accepts oil and opticon treatments for emeralds, such treatments must not contain dyes as green beryl that is not green enough is not qualified as emeralds and such stones have little value in the jewellery market.
|Mineral Class||Beryl variety|
|Hardness||7.5 to 8 on the Mohs scale|
|Refractive Index||1.565 to 1.602|
|Specific Gravity||Average 2.76|
|Transparency||Transparent to opaque|
|Lustre||Vitreous to adamantine|
|Cleavage||None, but may exhibit parting|
Techniques for enhancing colored gemstones, either detectable or otherwise, are continually being developed. These may be difficult, or in rare cases, impossible to detect, even for the most sophisticated laboratory. Reputable jewellers will continue to work with industry groups and gemological experts who are committed to the identification and disclosure of new and future techniques in order to maintain stringent quality standards.
While gemstones are durable, they require varying levels of care. For example, some gemstones are especially vulnerable to household chemicals and temperature changes. Cleaning gemstones presents special challenges. While many gemstones should be cared for by following our basic care guidelines below:
Cleaning: After removing your gemstone jewellery, clean it by following the directions on a non-abrasive jewellery cleaner. Make sure that the jewellery cleaner specifies that it is safe to use with your gemstone. Use a soft cloth to remove any remaining dirt or other residue.
Storing: Store your gemstone jewellery in a lined case or a soft cloth, so the gems do not touch each other or parts of other jewellery. Gemstones are harder than gold, silver, or platinum and can scratch the surfaces of your other fine jewellery if they are not kept separate.
Wear: While it's true that gemstones such as ruby and sapphire are second only to diamond on the hardness scale, it is not a measurement of their indestructibility. It means that these gemstones are able to resist scratching almost as well as a diamond. Abrasive surfaces, harsh chemicals, and sharp blows can damage even the hardest gem. Your gemstone jewellery should be the last thing you put on when getting dressed and the first thing you take off at the end of the night. Store your gemstones carefully and they will be enjoyed for generations.
Emeralds are an integral part of a more colorful gemstone market and specifically the bridal market, where we are seeing emeralds as both center stones and accent sidestones for engagement ring. Whatever your preference, this learning guide about emeralds will help you make the most informed decision on your next jewellery purchase.