Let’s talk about Emeralds and what they are. Emerald is a gemstone and a variety of the mineral beryl colored green by trace amounts of chromium or sometimes vanadium. Beryl has a hardness of 7.5-8 on the Mohs scale.
Most emeralds are highly included, so their toughness is classified as generally poor. Unlike diamonds, which have their own grading system, natural emeralds are considered to be one of the top precious stones with an ancient pedigree and are valued in a distinctly different way
If you are not a gemologist, the jargon and methods used to grade quality in gemstones can be hard to understand.
But do not worry, you need to know simple but important things that we wanted to educate you at here Vernon Jewelers that you should know about to make your purchasing decision.
For someone looking for an engagement ring for folks who love gems and want some ideas on what to look for, or for someone looking to give a gift to that special loved one. There are 4 important qualities of natural emeralds that you may want to know about
The green color found in emeralds is the main key factor in establishing both their value and quality. That unique green tint is exclusive to natural emeralds, and one that you will not find in other natural gemstones. Color is divided into: Hue, Tonal Grade, and Saturation.
The Color In Natural Emeralds: Hue And Tonal Grade
The green color found in emeralds is the main key factor in establishing both their value and quality. That unique green tint is exclusive to natural emeralds, and one that you will not find in other natural gemstones. Color is divided into: Hue, Tonal Grade, and Saturation.
Hue refers to the exact green color and emerald displays. Names given to various greens help us to visualize the subtle differences in the color lime green, pine, or forest, are all examples of this. The most desirable hue for an emerald is a pure green tone with no secondary colors such as blue or yellow.
Tonal Grade refers to how light or dark the color of an emerald appears. This can vary greatly from stone to stone and is determined by the amount of chromium present in the gem. The best tonal grades for emeralds fall between medium-light to medium-dark, as they allow for maximum saturation without being too dark.
Saturation refers to the intensity or strength of color in an emerald. A highly saturated emerald will have a vibrant and rich green color, while a less saturated one may appear duller and more muted in comparison. In general, higher saturation levels are preferred
The green tone establishes the degree of darkness or lightness of the green color in the gem. Natural emeralds present a wide variety of green tones. The most desirable emeralds are medium to dark green. Check out the diagram below.
Color Saturations and Clarity of Emeralds
How vivid and how much power the green has is as important as how dark it is. Color saturation is the strength of a color, from dull to vivid. For example, you will see how the emeralds in the following picture have a very close tonal grade but very different color saturation.
The richer the emerald’s color, the more it costs. Emerald prices soar as the depth and saturation of color increase.
As the right combination of ingredients can raise an ordinary recipe to gourmet status, the slightest variations in tone and saturation can make a tremendous difference in price. Also, clarity is another really important factor as we will see next.
The clarity in emeralds speaks about what the gem looks like on the inside and this is what makes an emerald a different gemstone than any other. Most emeralds present inclusions that are small bits of other minerals, gas, liquid, and crystals that the emeralds take on in the crystallization process. About 99% of all natural emeralds will present these features.
When looking closely, the inclusions in the emeralds are sometimes easy to see without a magnifying glass or microscope.
What in other gems may be considered “flaws” or “imperfections”, in emeralds is natural and is one of the things we try and look for every time we see them under a scope.
That is why gemologists, appraisers, and experts don’t use the same criteria to judge clarity in emeralds that they use for other gems like diamonds and topazes.
GIA (Gemological Institute of America)
GIA categorizes three clarity types for colored gems:
1.) Type 1 gemstones, often virtually inclusion-free, such as aquamarine, citrine, topaz, and green tourmaline.
2.) Type 2 gemstones, usually include things such as ruby sapphire, garnet, peridot, amethyst, and spinel.
3.) Type 3 gemstones, almost always include things such as emerald and red tourmaline.
Currently, mining companies are extracting the principal Emerald deposits in Colombia, Brazil, and Zambia. People also mine emeralds throughout the world, in other places such as Pakistan, Afghanistan, Russia, Australia, and the United States in areas such as North and South Carolina.
Colombia arguably produces the finest Emeralds in the industry.
Inclusions in Colombian emeralds most of the time appear as elongated and thin shapes with peaked ends. They are also called “Jardin” or gardens because they look like branches and plant roots. Like fingerprints, each emerald presents its own internal “garden” or layout for its inclusions.
Be sure to be careful and look closely so that they don’t look like bubbles, that they don’t look arranged in a specific order, and that they don’t appear in one specific spot in the gem.
When does clarity affect the price of an emerald? When it presents too many inclusions, when the gem does not look like a crystal because it is excessively included, and when it is too difficult to see facets on the pavilion, the back part of the emerald.
Inclusions can compromise the durability of a stone and lessen its value when they are close to the surfaces of the gem. Some inclusions can create fractures in the emerald. If any of these inclusions are at the surfaces the stone can be broken easily through that part.
In general, the fewer the inclusions, the higher the value of the gem. Of course, clarity is an important factor in evaluating an emerald but it is not the most relevant. Inclusions in emeralds are very special. Expect to find them. Any emerald without them is immediately suspected of being a synthetic or an imitation so keep that in mind.
Carat Weight
Most of the time when we indicate the size of an emerald we do it in carats. A carat is a unit of weight equivalent to 0.20 gems. Both are directly related and most of the time that we talk about size we talk about carat weight more than millimeters or inches.
1.0 carat (Ct.) = 0.20 grams
For people not familiar with jewelry and precious gems the term carat can be confused with “Karat”, which is completely different. The term karat is used as a measurement of gold purity (24 K gold, 18 K gold, 14k gold) and has nothing to do with the gem’s size or weight.
At the carat weight increases so does the price of the gem and most importantly, the price per carat of the stone. This can be calculated by dividing the stone price by its carat weight. Larger emeralds are rarer than smaller ones and very difficult to recover from the mines.
On average, they must remove 5 tons of ore for every gem-quality emerald over 1 carat. A 3- 3-carat emerald will cost more than three emeralds of 1.00 carat each of the same quality because they are exceedingly rare.
Durability
While some online information about emeralds indicates how delicate the gem is, in reality, emeralds are not at all fragile. The Mohs scale method identifies a gemstone’s relative hardness. For example, diamonds rank 10 at the top of the scale. Next are rubies and sapphire at 9; topaz at 8, while emeralds rank 7.5- 8.
That’s the same range as aquamarine, quartz, and tourmaline; and actually, harder than Tanzanite at 6.5 – 7. While emeralds are relatively durable, the presence of natural inclusions giving each stone a distinct personality and uniqueness can also affect their toughness. Liquids, gases, and crystals naturally occurring inside the gems create challenges for jewelers working with emeralds.
Gem cutters avoid touching inclusions with the cutting disk to avoid breakage. The setter who mounts the stone into a piece of jewelry can risk breaking the stone by forcing it into the setting if there are fissures (cracks) near a corner of the stone.
While all this talk may sound discouraging, fortunately, if you see an emerald whose inclusions are centered far from its surface or corners, then the gem’s durability is not a concern.
An expert cutter knows to isolate any inclusions in the center of the stone and the jeweler will design a setting that protects the stone so it is least likely to get bumped under normal wear.
Yes, emeralds may be somewhat fragile but good cutters and setters like us here at Vernon Jewelers have already made accommodations to protect the stone for the wearer.
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