Triple X diamond is a trade term referring to stones that have Excellent cut, polish and symmetry on their GIA grading reports. GIA does not use this term but many jewelers do. Does Triple X rating matter and should you pay more for a Triple X diamond? (more…)

A GIA diamond cut grade is key to knowing how well your round brilliant diamond will sparkle. Cut is the most complex of a diamond’s 4Cs. Let’s cover some essentials so you can pick the perfect round brilliant diamond engagement ring.

In this blog, we cover:

1. Diamond cut quality and why it’s important
2. What goes into a GIA diamond cut grade
3. Diamond sparkle and face-up appearance
4. Why diamond proportions are important
5. Design, craftsmanship and the GIA diamond cut grade
6. How GIA assigns a diamond cut grade

1. Diamond cut quality and why it’s important

The most popular diamond in the marketplace is the round brilliant. Experts estimate that this cut alone accounts for more than 70% of all diamonds sold today. The quality of a round brilliant diamond’s cut determines how much the diamond sparkles. To pick a diamond whose flashes of light enchant the eye, you need to know the 4Cs of diamond quality, the universal standard for judging diamonds: color, cut, clarity and carat weight. All else being equal, the better the cut grade, the more valuable the diamond.

Some professionals consider cut the most important C of diamond quality. A well-cut round brilliant delivers that unmistakable, stop-in-your-tracks light show that telegraphs “diamond” across a crowded room. If the diamond is well cut, most compromises in clarity, color and even carat weight can be forgiven. A diamond’s cut grade is also an indication of how well it was designed and crafted. So, understanding the diamond cut grade is key to picking a round brilliant that’s not only beautiful, but also the best value.

2. What goes into a GIA diamond cut grade

In arriving at its cut grading system, GIA spent 15 years studying how light behaves within a round brilliant cut diamond. GIA’s aim was to understand the factors that contribute to a round brilliant’s appearance and to determine which of those factors – or combination of factors – produce diamonds that people consider attractive.

GIA’s research included the use of advanced computer modeling to analyze tens of thousands of possible proportion combinations. GIA then validated its research with human subjects, conducting more than 70,000 observations on actual diamonds, to determine which diamonds people found appealing and why.

The result was the GIA Cut Grading System, which evaluates the cut quality of a round brilliant diamond along a five-point scale ranging from Excellent to Poor.

A GIA cut grade evaluates:

1. How the diamond appears when viewed face-up based on the attributes of brightness, fire and scintillation
2. How well the diamond was designed to ensure durability and optimal weight
3. The quality of the workmanship or craftsmanship that went into aligning and polishing the diamond’s facets

The GIA diamond cut grade is based on seven factors: brightness, fire, scintillation, weight ratio, durability, polish and symmetry.

This 2.02 carat (ct) round brilliant has excellent cut, polish and symmetry. Courtesy: 1stdibs.com

The reason behind the sparkle of this 1.01 ct round brilliant cut diamond engagement ring is the quality of the diamond’s cut. The diamond received an Excellent cut grade from GIA. Courtesy: 1stdibs.com

3. Diamond sparkle and face-up appearance

A key component of a GIA diamond cut grade is the diamond’s face-up appearance – or how the diamond looks when viewed from above, as if it was set in an engagement ring. People love diamonds for their dazzling interplay with light – which the layperson often translates as “sparkle.” But there’s a lot more going on here.

When you see internal and external white light reflected from a diamond, you’re noticing “brightness.” If you see the scattering of light into all the colors of the rainbow, you’re being treated to “fire.” Sparkle is actually “scintillation,” the pattern of bright and dark areas caused by reflections within the diamond as it or the light source moves. What you might consider “sparkle” is really the overall visual effect of these three factors. A GIA cut grade includes an assessment of how well a diamond delivers on each of these attributes.

This round brilliant cut diamond shows good brightness and fire. Scintillation, the pattern of light and dark areas and the flashes of light, or sparkle, can only be seen when a diamond is moved. Copyright: GIA & Harold and Erica Van Pelt

4. Why diamond proportions are important

A diamond’s proportions – its crown and pavilion angles and the relative measurements of its facets – are key contributors to a diamond’s overall face-up appearance. Remember that facets are tiny mirrors. Their size and placement will influence how light behaves as it passes through the diamond and back to your eye.

A diamond’s proportions can help predict how well a diamond will deliver brightness, fire and scintillation. However, an important outcome of GIA’s cut research was the finding that there is no single set of proportions that defines a well-cut round brilliant diamond. In fact, diamonds with different proportions can receive the same cut grade. The diamonds may look and perform differently but they will still have a similar impact on the observer. So, as a diamond shopper, you need to look beyond the measurements on a grading report. Be sure to view a diamond in person to see if it’s the right choice for you.

This graphic illustrates the proportions that affect a diamond’s cut grade. The crown and pavilion angles and the relative measurements of its facets contribute to a diamond’s brightness, fire and scintillation.

5. Design, craftsmanship and the GIA diamond cut grade

While face-up appearance is all about how a diamond looks, design and craftsmanship evaluate the quality of the diamond’s manufacture. Poor design could add unnecessary weight to a diamond or cause durability issues that would prevent you from enjoying it for a lifetime. A diamond with poor craftsmanship won’t deliver much in the way of brightness, fire and scintillation. In evaluating these two components, the GIA Cut Grading System takes into account the diamond’s physical shape, its proportions, its weight ratio, and the care that went into fashioning and polishing its facets.

Design
Design refers to decisions made during the fashioning process that determine the diamond’s physical shape, as seen in its proportions, weight ratio and durability. Weight ratio is the diamond’s weight in relation to its average girdle diameter (a fairly complex mathematical equation). A diamond with a smaller girdle diameter relative to its weight might appear smaller face-up than its well-designed counterpart, because much of the weight would be “hidden” in the overall depth of the diamond. For example, while a diamond with a thicker girdle could look great, the girdle is hiding unnecessary weight. As a result, you might end up paying more for a heavier diamond with no greater visual impact for the added cost. The bottom line: A diamond should not weigh more than its face-up size would indicate.

These pictures show the importance of weight ratio. Both of these diamonds have the same average girdle diameters, so face-up they appear to be the same size. But the diamond on the right has a much thicker girdle, so it weighs more (0.71 ct vs. 0.61 ct). The thicker girdle has no visual benefit, but the added weight will make the diamond more expensive. Photos: Maha Tannous/GIA

Durability in the case of a round brilliant diamond refers to the risk of damage that might result from an extremely thin girdle. Such a girdle can make a diamond highly vulnerable to damage during the jewelry setting procedure or even normal wear. Considering how much a diamond costs and its emotional significance, you want to avoid one that is susceptible to damage. A GIA Diamond Grading Report can eliminate this concern.

Here is an example of why durability is important. This 1.35 ct diamond has girdle areas that are very thin to extremely thin, making it more susceptible to damage during everyday wear. Courtesy: Gary Roskin, G.G., F.G.A.

Craftsmanship

Craftsmanship describes the care that went into fashioning the diamond, as seen in its polish and symmetry. Polish refers to the overall quality and condition of the facet surfaces. It includes evaluation of any blemishes created by the polishing process or during wear. Polish is critical to the mirror-like performance of a diamond’s facets.

The diamond on the left shows lines created during the polishing process. The diamond on the right has abraded facet junctions caused by wear. Polish lines and abraded facet junctions can also affect a diamond’s clarity grade. Photos: Mitchell Moore/GIA

Symmetry is the exactness of a finished diamond’s shape and the arrangement and placement of its facets. A symmetrical diamond has an even display of brightness, fire and scintillation. A diamond with poor symmetry will have poor light performance, meaning that it’s likely to look flat.

All eight sections of a round brilliant cut diamond should be identical. This symmetry will help produce even brightness, fire and scintillation. Illustration: GIA

6. How GIA assigns a diamond cut grade

GIA evaluates a round brilliant diamond’s cut based on seven components – brightness, fire, scintillation, weight ratio, durability, polish and symmetry – to arrive at a GIA diamond cut grade, which ranges from Excellent to Poor. The grade is set by the lowest assessment the diamond receives for five of the seven components. In other words, if a diamond receives a Poor grade for brightness, then the highest its overall cut grade can be is Poor. The exceptions are polish and symmetry, which are assessed using standard GIA grading methodology: A diamond with Very Good polish and/or symmetry, for example, may receive an Excellent cut grade.

A GIA Diamond Grading Report contains the diamond’s full cut assessment, in addition to a diagram showing the diamond’s proportions and relative measurements. Consider the report an invaluable tool in helping you pick a dazzling diamond.

The official GIA Cut Scale for round brilliant cut diamonds. Illustration: GIA

While knowing a diamond’s cut grade is essential, it shouldn’t be a substitute for seeing a diamond in person. As mentioned above, a diamond cut grade represents a range. For example, two diamonds with an Excellent Cut Grade may look – and perform – very differently. In addition, a diamond will look different under various lighting conditions, so you should take it for a test drive, so to speak. Last, you need to fall in love with the diamond – and no report can substitute for what stirs your heart.

An Excellent cut grade makes this 2.03 ct round brilliant diamond mesmerizing. Courtesy: 1stdibs.com

Diamond cut is extremely important. So is diamond color. Learn about it, too, so you can pick a spellbinding diamond.

Diamond sparkle might be one of the most-desired requirements for an engagement ring. A diamond’s breathtaking light show is one of the reasons we love this gem. But finding a diamond that sparkles requires some knowledge. So let’s get to it!

In this post, we’ll cover:
What Makes a Diamond Sparkle
How to Choose a Diamond that Sparkles
Maximize Diamond Sparkle – What Works/What Doesn’t

A pavé set diamond halo surrounds a center stone, creating numerous opportunities for sparkle. The diamonds weigh a total of 1.46 carats. Courtesy: 1stdibs.com

What Makes a Diamond Sparkle?

The short answer: light’s interaction with a diamond’s cut. The type and quality of the cut govern how a diamond reacts to the light around it. The angles and relative measurements of a diamond’s facets, as well as its other proportions, have a dramatic effect on how light performs when it strikes a diamond.

The long answer: You probably use the word “sparkle” in a very general way to describe the overall visual effect of a diamond’s interaction with light. But gemologists who have closely studied diamond’s signature light show break it down this way:

When light enters a diamond, it travels through it, reflecting off its interior surfaces, called facets. It then either leaves the diamond as white light, called brightness, or it divides into the spectral colors of the rainbow: red, orange, yellow, green, blue and violet, called fire.

Light leaving a diamond as spectral colors can be quite breathtaking. Copyright: GIA and Harold & Erica Van Pelt.

As you or the diamond moves, an effect called scintillation occurs – visible as alternating flashes of white and spectral-colored light and the contrast of dark and light that moves around the diamond. This contrast is dynamic and causes, in layperson’s terms, sparkle.

How to Choose a Diamond that Sparkles

Since diamond sparkle is all about how well the stone interacts with light, the environment in which you view the diamond and the diamond’s cut quality are critical.

1. Be sure to examine the diamond under four different light sources. Spot lighting (or a lot of individual light sources) is the best way to see all the elements that produce sparkle. However, if there are too many spot lights and they are too bright, there will be so much glare that one diamond will look just as good as any other.

To avoid this, observe the diamond in an environment where the spot lighting is not overwhelming. Then look at the diamond in diffused lighting — fluorescent lights that bounce light off a white ceiling are best. Third, try to view it in a mixed lighting environment of spotlights and diffused lighting. And, finally, don’t forget to view the diamond in natural daylight.

Learn more about how light affects the appearance of a diamond.

A 1.52 carat (ct) round brilliant diamond is a visual delight in this engagement ring. Courtesy: EraGem

2. Pay attention to cutting style. The more facets a diamond has, the more reflective surfaces there are to bounce and scatter light. A round brilliant cut diamond with its 57 or 58 facets will appear to have more sparkle than a single-cut diamond with only 17 or 18 facets. Learn how to pick a round brilliant diamond engagement ring.

If you have your heart set on a shape other than round, you can still get the sparkle if you look for diamond shapes cut in the brilliant faceting style. These include princess, radiant, oval, pear, heart and marquise.

This 8.06 ct Asscher cut diamond from Cartier, circa 1935, is spectacular. Courtesy: 1stdibs.com

3. Pay attention to cut quality. There’s another solution for standard round brilliants, if you’re unsure about judging a diamond’s sparkle. A GIA Diamond Grading Report can be of great value in finding a diamond that sparkles. GIA issues one of five cut grades for a round brilliant diamond: Excellent, Very Good, Good, Fair and Poor.

A diamond with an Excellent cut grade is very bright. It shows an even pattern with good contrast between light and dark areas, so the reflections appear crisp and well balanced. This tells you that the cutter created the best possible stone from the rough.

A Very Good cut grade means the diamond has bright areas evenly distributed across the stone’s crown and few distracting areas.

A diamond with a Good cut grade isn’t quite as bright – reflections aren’t as sharp and there’s more darkness or dullness in the diamond.

A diamond with a Poor cut grade has much more prominent dark areas or dullness. Given the choice, most people would pick diamonds with either Very Good or Excellent grades.

This diamond has an Excellent cut grade: It is very bright and shows an even pattern with good contrast between light and dark areas. Reflections appear crisp and well balanced. If all else is equal, an Excellent cut grade pretty much guarantees an extremely attractive diamond. Photo: Al Gilbertson and Barak Green/GIA.

This diamond has a Good cut grade. Its bright-reflections aren’t as sharp and there’s more darkening around the girdle. Photo: Al Gilbertson and Barak Green/GIA.

This diamond has a Poor cut grade. It has significantly more prominent dark areas; there’s a much smaller bright area. Photo: Al Gilbertson and Barak Green/GIA.

Learn more about how GIA grades diamond cut.

Maximizing Diamond Sparkle – What Works/What Doesn’t

Looking for more visual bang for your buck when purchasing a diamond engagement ring? Here are some tips for getting the most diamond sparkle.

1. Bigger is not necessarily better. You may think: the larger the diamond, the more sparkle. But in reality, diamonds with identical proportions, color and clarity have the same amount of sparkle regardless of size. Visually, you might perceive a difference when comparing two diamonds that are dramatically different in size. For example, a 0.25 ct diamond may appear to sparkle less than the 1.00 ct diamond next to it. But when it comes to choosing a diamond, typically you’re making a selection between diamonds that fall within a narrow size range, so slight differences in diamond size would have no effect on your perception of sparkle. Again, this assumes the cut quality of the diamonds being compared is the same.

Talk about sparkle! This three-stone engagement ring seems to have it all. A marquise-shaped diamond in the center is flanked by two half–round brilliant cut diamonds, all of which are surrounded by more diamonds in a pavé setting that extends along the ring’s shank. Courtesy: ZIVA Jewels Inc.

2. Choose a diamond with good color and clarity. Researchers have found that brightness diminishes in diamonds that grade lower on the D-to-Z color range. Likewise, clarity issues in diamonds graded SI2 or I can diminish the appearance of fire. Both will reduce the sparkle in a diamond.

3. More diamonds, more sparkle. Definitely yes! More diamonds, whether big or small, will add more sparkle to your engagement ring. This is one reason why diamond side stones and pavé settings are so popular.

4. Pick the right setting. If you’re looking for a bigger visual display, a prong setting is better at allowing light to enter the diamond than bezel settings that cover more of the top surface of the diamond. Learn more about different setting styles.

You can have lots of sparkle and still have a simple ring design. This solitaire engagement ring by Tiffany & Co. features a 2.28 ct round brilliant diamond. Courtesy: Pampillonia Estate and Fine Jewelry

5. Keep the diamond clean. This is probably the most important (and affordable) tip. A diamond that’s dirty will not sparkle. Diamonds have an affinity for grease, so it’s important to clean them regularly. Find out how to keep your diamond clean.

In the end, nothing adds sparkle to an engagement ring like the love with which it’s given. So follow your heart and relish the moment — you really can’t go wrong.

If you need a little extra help as you shop, check out our glossary of common engagement ring terms. They’ll help you better communicate your needs and desires with a jeweler.

If you’re asking, “What is the most important C?”, chances are you’re already well into the process of purchasing a diamond engagement ring. When it comes to diamond quality, the answer is simple, but not necessarily straightforward. (more…)