A Guide to Emerald Cut Diamonds

As the saying goes, “variety is the spice of life”. This is certainly true in the world of diamonds. While the round brilliant is the shape most closely identified with diamonds, these incredible little crystals of pure carbon are cut into a wide range of shapes and facet arrangements. This gives rise to many diamond “flavors”, some as different from one another as chocolate and strawberry. The emerald cut diamond is one of the most distinctive of those flavors in both shape and optics. In this article we will explore the unique beauty of the venerable emerald cut diamond.

* While the information below is predicated on natural Earth-mined diamonds, it also pertains to lab grown diamonds with some of the differences  between the two also discussed.

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Emerald cut diamonds have long been considered the most elegant diamond shape. They are very distinctive in their overall look and in the type of optics they generate. Their step cut facet design creates an entirely different visual sensation than the ubiquitous round brilliant and the many brilliant style shape variations available. The emerald cut features a series of horizontal step-like facets, as opposed to the vertical facets of brilliant styles. Its four longer sides have beveled corners with two, three, or four concentric rows of facets, parallel to the girdle, on the crown and pavilion. In this article you will see how this unique facet style impacts light performance, and what to look for in this venerable diamond cut prized as a classic for its old-world opulence.

If you are in the market for an emerald cut loose diamond, the information below will help you in selecting a great stone for your taste and budget. We will discuss aspects of the 4 C’s such as clarity, color and especially cut quality, that will be key to choosing a great diamond. We will also discuss taste factors such as length to width ratio, as well as touching on style considerations for emerald cut diamond rings. And we will discuss prices for natural emerald cut diamonds. (Lab grown diamond pricing is driven by very different factors).

The overall shape of an emerald cut can vary dramatically from the square Asscher shape to very elongated emerald cut. To a large degree the outline of the shape is a matter of personal taste. Some prefer a long slender shape, others a wider rectangular shape. Most people prefer something in the middle – a balanced rectangle with a length/width ratio of about 1.4.

An emerald cut is an octagon with four sides and four corners. The overall length to width ratio (length in millimeters divided by width in millimeters) is very important in determining the visual appeal of the shape, but the size of the corners have a visual impact as well. They can be very small, lightly clipped corners or large corners the size of the other sides.

A unique variation of the emerald cut is the Asscher cut. This distinctive square facet arrangement with its wide corners was developed and patented in the early 1900’s by Joseph Asscher. The patent has long since expired and the shape is now referred to on lab reports as a ‘square emerald cut’.

The symmetry of the cut gives it a unique appeal. The x-like facet pattern extending from the corners to the culet is often referred to as the ‘windmill’.

The facet design of an emerald cut is particularly revealing of any inclusions that might be present in the diamond. Brilliant style facet arrangements that promote fast scintillation tend to camouflage inclusions, particularly around the crown. The emerald cut with its relatively large table facet acting like a window and long step facets with slow scintillation make inclusions relatively easy to see. This is the reason that you tend to see emerald cuts in the higher clarity grades. Lower clarity diamonds are typically cut into other shapes that will conceal inclusions better. This factor tends to make natural emerald cuts more expensive than most other fancy shapes. (This factor is not applicable to lab grown diamonds)

Whereas many shoppers looking for best bang for the buck focus on Si clarity when shopping for rounds, it is likely that value shoppers looking for a natural emerald cut will need to focus on VS as a baseline.

Because the emerald cut does not exhibit as much brightness as a well cut round, it tends to show its body color more prominently. A round returns almost all of the light entering the crown and in a bright environment the body color of the round is overwhelmed by the ambient light being returned to the eye. Similar to how it shows inclusions more readily, an emerald cut tends to show true body color. That color is also sometimes trapped and concentrated in the ends of the stone, depending on its proportions. This again means that emerald cuts tend to be made from higher color rough, adding to the likelihood that a suitable emerald cut will be more costly, even though price per carat is generally lower for non-round shapes, quality for quality.

Whereas value shoppers often find suitable diamonds in the lower near colorless range I-J, those looking for emerald cuts should focus in the upper near colorless range of G-H.

The step cut facet arrangement produces much less scintillation than brilliant style cuts such as hearts and arrows diamonds. The large horizontal facets of the emerald cut produce large and relatively slow flashes, rather than the smaller faster sparkle of brilliant styles.

While not as sparkly, a well cut emerald cut produces bold white flashes and color sparkles (fire) which are very impressive. Overall, the slower, bolder optical effects of the emerald cut appeal to many as more sophisticated than the frenetic blaze of sparkle that spins out of a brilliant cut. The emerald cut has a very distinctive flavor, and for some people it is the ultimate in diamond beauty.

The Angular Spectrum Evaluation Tool (ASET) developed by the American Gem Society Laboratories (AGSL) provides a graphical view of light performance that can be utilized with any diamond shape. It reveals aspects about the quantity and quality of the light that a diamond is returning to the eye. While the types of images revealed by ASET are well understood in round brilliant diamonds, and to a lesser degree other shapes with brilliant style facet arrangements, accurately interpreting ASET signatures on emerald cut diamonds requires more experience.

Below are three sets of images for emerald cuts; from left to right ASET, Diamond Image, and IdealScope . All three are very nice diamonds, but the ASET signatures show important differences in their light performance. One has a light leakage issue, one has too much concentrated contrast, and the third has nice optical balance. Learning how to interpret ASET images for fancy shapes is a significant benefit to diamond shoppers looking for the most beautiful diamonds.

The AGSL has developed the most sophisticated scientific method to evaluate cut quality. Their light performance based system involves computerized ray tracing of 30,000 virtual light rays on a 3D model of the diamond to measure the amount of brightness, fire, contrast and light leakage. Diamonds that have an optimal amount of each factor are awarded a cut grade of Ideal.

While most emerald cut diamonds on the market have lab reports from GIA, they do not include an overall cut grade because a GIA cut evaluation system for fancy shapes has not yet been developed. Only GIA reports on round diamonds come with an overall cut grade. For more info on the differences between these two top tier gem labs, please see our article on AGS vs GIA.

Because crafting emerald cuts for optimal light performance requires more skill, time and expertise, most manufacturers have determined that it is not economic to cut to Ideal parameters, given the relatively small market for the shape. That may change over time as more consumers come to appreciate the importance of cut quality.

Below is a sample of an AGS Platinum light performance-based grading report on an Ideal Emerald Cut. As with all Platinum reports from AGS Laboratories the document features an accurate computer generated ASET light map of the diamond.

The basis for natural diamond pricing is the weekly Rapaport list. Manufacturers and dealers use this guide as a starting point for trade pricing, which ultimately determines pricing at the retail level. There are two lists, one for rounds which are generally priced higher, and the “pear shape” list on which all fancy shapes are based. The pear list is lower on a per carat basis than rounds by significant margins. Normally, going with a non-round shape is a way then to get more diamond for less money. But as we have seen, there are characteristics inherent with emerald cuts that tend to preclude finding them for big savings. Generally speaking you will have to step up to a higher color and clarity with an emerald cut than may be otherwise acceptable in round.

*The price sheets above are presented solely as examples of how prices are presented to the trade. They are not current and have no relevance to the present market for natural diamonds, and have no bearing on lab grown pricing.

The two most popular rectilinear diamond shapes are the emerald cut and the princess cut. Though they share some shape attributes, the looks could not be more different. As we have seen the emerald cut is a step-cut facet design whereas the princess is a brilliant style. The pavilion of the princess has main facets that are vertical along with angled chevron facets. This gives rise to a splintery type of brilliance and sparkle akin to the round brilliant, just with a square outline. The emerald cut on the other hand has longitudinal step facets on the pavilion and the crown which produce long, broad flashes. The scintillation patterns of the princess feature small fast flashes. The emerald cut features a soothing understated elegance while the princess is a high frequency sparkle bomb by comparison.

Shoppers are frequently interested in getting the biggest look they can for their budget. While natural emerald cuts are theoretically less expensive than rounds, the need to stay in higher color and clarity ranges tends to negate savings. That is, you will probably need to target a slightly smaller diamond for a given budget. However, they do tend to look a little bigger because of their length to width ratio. An emerald cut diamond ring can give more finger coverage as the diamond extends further down the finger.

The proportioning of an emerald cut can also determine if the diamond is “spready” with a good surface area for its weight. You can find them with relatively flat crowns and shallow pavilions which will maximize the outer dimensions of the diamond. However, there is a cost in optics in cutting any diamond too thin. It will result in a loss of light return and/or fire.

If you are shopping for an emerald cut diamond, it is highly recommended that you work with a vendor who has expertise in cut quality and who can provide the thorough evaluations including advanced light performance diagnostics demonstrating the light handling properties of the diamond you are considering.

As we have seen, the emerald cut has a very distinctive appearance. Here are some quick list of considerations to weigh in deciding if this is the shape for you.

One of the exciting things happening in the diamond industry today is the emergence of lab created diamonds. While previously used primarily in the abrasives and for some high tech applications, the last several years has seen massive innovation in the production of larger, gem quality diamonds.

Quantities of high quality lab grown diamonds are now being brought to market in a wide variety of shapes and sizes, and at prices that make them a very affordable option for many diamond shoppers. One of the outgrowths of this trend is that it enables many diamond lovers to experiment with different shapes, and lab created emerald cut diamonds are among the most popular.

A lab created emerald cut diamond ring is a real attention getter with it’s elegant, slow flashes of white and colored light. It is both different and distinctively attractive with its unique flavor of light performance. And compared to the price of comparable natural diamonds, tantalizingly affordable!

Lab grown diamonds are real diamonds with essentially the same chemical, physical and optical properties as natural diamonds. Therefore they have the potential to be just as durable and beautiful, provided the material is fully transparent and cut with precision. Besides the obvious price difference, some of the other differences that shoppers need to be aware of are discussed on our lab grown diamonds page.

One of the benefits of an emerald cut diamond ring is that it lends itself to architectural designs that are different from the ubiquitous round styles. For someone who wants to stand out from the crowd, and create something really unique, an emerald cut can be just the ticket. The clean straight lines the outline and the flash patterns of the emerald cut can be incorporated in geometric design concepts that really capture a holistic beauty different from the mainstream.

As unique as they are, emerald cut diamonds are more versatile than you might think. They look elegant as solitaires, stand as bold centerpieces for elaborate halo and pave settings, and are quite at home in vintage designs.

This magnificent Tacori design has it all. It presents in a classic solitaire form, but is embellished in an ornate pave style with a halo slightly softening the angularity of the emerald cut and creating an unmistakable vintage sensibility. Distinctively classy and bright!

While it is certainly possible to walk into a jewelry store and shop for a natural emerald cut diamond ring, chances are the selection will be extremely limited. This is why shoppers looking to avail themselves to the best available options tend to shop for emerald cut loose diamonds online.

In addition to looking at the details of the diamond in the listing and the laboratory report associated with it, astute shoppers are looking for more comprehensive diagnostics including magnified photo, 360 video, and light performance images including ASET and Ideal Scope. Moreover, you want to be sure that you can get expert consultation from a vendor who is knowledgeable about emerald cuts.

Whiteflash is a great place to shop for diamonds with full confidence because we provide all the diagnostics you will need to make an educated purchase, including thorough gemological analysis and light performance imaging. We offer, among many other benefits, a money back return period to have your Whiteflash purchase reviewed by an independent expert if you so desire. The diamond consultants you deal with at Whiteflash are all credentialed from the GIA and have years of experience helping online shoppers make brilliant choices. Best of all, none of them work on commission. Their sole purpose is to help you find the best diamond for your criteria and budget.

We hope this guide has been helpful. The Whiteflash Teams wishes you good luck on your diamond journey. We hope it is a brilliant one!