Emerald guide

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. Since it’s all about the color, you need to buy your emerald from a site that has high quality images of their stones.

The Importance of the Four C’s

As you probably know already from other guides on our site, we encourage readers to learn about the importance of the 4 c’s when purchasing diamonds.Though we use the same 4 c’s 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 4 c’s. 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.


Emerald with Moderate Tone and Weak Saturation

color is really broken up into three categories: hue, tone, and saturation.


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.


Emerald Tone

The tone of the emerald classifies the stone in terms of light and dark. Natural emeralds fall somewhere in the spectrum between Very Light and Very Dark. 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.


Emerald Saturation

This is what gives the color its intensity and strength. Saturation can range from dull to pure 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.

Emerald with storng Tone and Strong Saturation

Bottom Line

The bottom line to remember here is that the darker tonal 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.


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 (see our article on diamond clarity here), 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.

Mind the Inclusions

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.

Emerald Treatments

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.

Emerald vendors generally accept the use of oil, but do not look favorably upon green-tinted oil. All emeralds sold should have full disclosure of treatment according to the US Federal Trade Commission.


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 carat stone will be more expensive than a 1 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. And beware that there will be a big price jump once you hit 1 carat since it takes, on average, the removal of five tons of dirt to find a gem-quality emerald over 1 carat.

Considering Certificates

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.

GIA Classification

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.


Ruby guide

If you are considering buying a ruby to be set in a ring, earrings, pendant, or other jewelry, then here’s our how-to guide of how to buy the best ruby for your money.

We will go through the 4 c’s in order of their importance




Oval Cut Ruby with Pure Red Hue

As with emeralds, the most important factor when evaluating a ruby is its color. The deeper, and more intense the color, the better. Basically we measure color using three criteria: hue, tone, and saturation.

Hue refers to where the ruby falls in the spectrum of other colors. Each ruby has a primary and secondary color. The primary color is red, and the secondary color is usually orange, purple, or pink. The more the ruby’s color is strictly red, the more valuable the ruby.

Secondary Colors


Oval Cut Ruby with Purplish Hue

Some rubies mined from specific locations are known to have certain secondary colors, like rubies from Myanmar that have a slight purple secondary color. Purple as a secondary color can actually be better because it makes the red appear richer. (Another color tip: set a purplish red ruby in yellow gold like they do in Burma so that the yellow color will neutralize the blue in the purple, thus making the ruby appear even more red.)

Ruby tones

Tone refers to how light or dark the shade of red is, with most good quality rubies falling somewhere between medium and medium dark tone. If the ruby’s color is too dark, then it’s difficult to make out the color, and if it’s too light than the color will be too faint.

Also, if a ruby’s tone is too light, it might be considered a pink sapphire — even if the stone has high saturation.

Ruby saturation

Which brings us to our last criterion, saturation. This refers to the ruby’s depth of color, or how intense the color is. The more intense the color, the more precious we consider the ruby; a well saturated ruby will most likely be either “strong” or “vivid.”

Also, rubies that fluoresce (glow in ultraviolet light) can have even greater saturation. And rutile needles, which are tiny inclusions, may improve the ruby’s color by reflecting light from inside the stone. It should go without saying that if the color of a ruby is by far the most important factor, it would be crazy to even consider buying a ruby sight unseen.

No objectice grading system

But unlike diamonds that are graded according to a strict system of letters starting with “D” and going on through alphabet, colored gemstones have no objective grading system. Gemological laboratories use master stones in order to contrast other stones’ hues, tones, and saturations. This is the only way, for example, gemologists can distinguish between pink sapphires and rubies. But it also leaves some room for error, so beware of these murky waters if someone is trying to sell you a ruby that looks a lot more to you like a pink sapphire!


Clarity refers to the number, size, color, location, and quality of imperfections in the stone, known as inclusions. When gemologists measure the clarity of diamonds, they use 10x magnification to get a super-magnified view of the inside of the stone.

With colored gemstones, however, gemologists do not use magnification; rather, they look for what we call “eye-cleanliness,” which means that the stone is clean or free of inclusions when viewed by the naked eye. The better the clarity, the more expensive the ruby.

All natural rubies will contain some level of inclusions, also known as rutile needles or “silk.” If there are no rutile needles, gemologists will suspect the ruby has been treated, or is synthetic.


A ruby’s cut refers to how the stone is faceted, its dimensions, and overall symmetry. Unlike with diamonds, rubies are not graded on cut quality. The cut is much less important to consider than the ruby’s color and clarity. But as is the case with most gemstones, the true glow of the ruby is only revealed after a quality cut that maximizes light return and color. There are four factors gem cutters must keep in mind when cutting sapphires and rubies.

1. Maximize color.

2. Maximize carat weight.

3. Minimize inclusions.

4. Keep in mind what shape the consumer wants, i.e., round, oval, pear, cushion, cabochon, etc.


And finally, let’s consider the ruby’s carat weight. As you probably already guessed, the more carats, the bigger the price tag. Since larger gemstones are rarer than smaller gemstones, you pay more based on the laws of supply and demand.

Having said that, you should also be aware that there are usually price jumps when you hit one carat, as well as three and five carats. If you want to buy a one carat ruby, consider going for a 0.9 ct. instead since most likely you will not notice the difference in size once set, but you will notice the savings in your wallet!


Sapphire guide

Buying a Sapphire is much less technical than buying a diamond. Diamond’s are treasured for their brilliance while sapphires are loved for their color. Since it’s all about the color, you need to buy your sapphire from a site that has high quality images of their stones.

Let’s take a look at the 4 C’s of sapphires in their order of importance.



Color is the most important factor when purchasing a colored gemstone. The color of the sapphire is what captivates us, and draws us in for a closer look.

But this is only when the color of the stone has the proper measures of hue, tone, and saturation. Without these, the stone may appear dull, colorless, and gray.

Sapphire with Great Saturation


Sapphire with Weak Saturation

A sapphire’s hue describes the stone’s balance of color as it relates to its neighbors on the color wheel. With blue sapphires, for example, we would call the stone’s color either blue, slight green, strong green, slight purple, or strong purple.

The closer you can get to “true” blue, the more expensive and desirable the sapphire will be.

Sapphire Tone and Saturation

Tone describes how light or dark the color is with the range going from very light to very dark. It’s best to stay in the medium to dark range with tone, as the lighter the tone, the more watered down the overall look of the sapphire. And finally, the saturation describes how vibrant the color is with the range going from dull/weak to pure vivid. The closer to pure vivid you can get, the better the sapphire’s color will appear to you, and the more money it will fetch. As we said, the most desirable sapphires will have vivid, highly saturated color without areas of brown or gray. These areas are known as extinction and are affected by lighting quality, position, tone, and cut. Usually the darker the stone’s color, the darker the extinction will be as well.

Color Grading Issues

Whereas diamonds have an elaborate, standardized color-grading system, sapphires and other colored gemstones have no such similar way to assess color across the board. This lack of uniformity means that it’s harder to compare two sapphires since one won’t be graded “D” and other “J.” Rather, you will have use your own judgment about which colors appear vibrant and alive to you. Of course, the better the sapphire’s color, the higher the price tag will usually be, but be sure to buy only from reputable gemstone vendors.


It is highly unlikely to find sapphires without any inclusions, or imperfections, at all. If there are no inclusions, gemologists will suspect the sapphire to be fake or treated. As we explained in our guide about rubies, all sapphires will have rutile needles or “silk”.

Most sapphires on the market today have been heat-treated to improve their clarity and color. (If they’ve not been treated at all, they can be sold for big money.) Whereas with diamonds, gemologists use 10x magnification to inspect the diamond’s inclusions, with colored gemstones, we are only concerned with non-magnified careful examination.In other words, we are looking to see if the stone is “eye-clean” to the naked eye. The cleaner the stone, the higher the price tag.



There are no standardized cuts for sapphires as there are with diamonds. Whereas with diamonds you could choose an “ideal” cut to showcase the diamond’s color and fire, with sapphires — and most colored gemstones — you are relying on the gem cutter to maximize each individual sapphire’s unique combination of color, clarity, and brilliance. In general, a well-cut sapphire will be symmetrical and reflect light at the proper angles in order to enhance the stone’s luster. It is often the case that gem cutters will cut more deeply when the sapphire’s tone is light. This makes the stone appear to have a deeper, darker color. And the opposite is also true: if the sapphire is very dark, then the gem cutter may choose to make a shallow cut to bring more light in and thereby lighten the overall look of the stone.


Just as gemstones vary widely across the spectrum in terms of their color and hardness, so too they also differ in density. This is apparent when we consider the carats, or weight of the sapphire vis a vis the carat weight of a diamond. Since sapphires are usually heavier, a one carat sapphire will look smaller than a one carat diamond. It is more accurate to measure the size of the sapphire in terms of its millimeter diameter. A rule of thumb is that a one carat sapphire generally measures 6 mm.

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Guy Tsur Online Private Jeweler