Emerald Cut Diamonds | Guide, Proportions, L/W Ratios

This guide provides a comprehensive insights on emerald cut diamonds, including guidance on ideal cut proportions, clarity, color, fluorescence, and certification.

The emerald cut is a type of diamond cut featuring a step-cut with facets arranged in a rectilinear style parallel to the girdle, creating a staircase-like appearance. This cut addresses the weakness typically found at the corners of diamonds, making it a desirable choice. Additionally, the emerald cut diamond features a keel running through the pavilion terminus, a unique characteristic not found in other diamond cuts.

This style of diamond cutting dates back to the 13th and 14th centuries when diamonds started gaining popularity. Modern emerald cut diamonds have 49 facets or more, with roughly 25 on the crown, 25 on the pavilion, and eight on the girdle, forming three rows of bottom and top steps.

During the Art Deco period, many antique jewelry pieces showcased step-cut styles, which has contributed to the enduring appeal of the emerald cut diamond. If you appreciate classic styles commonly found in antique jewelry, an emerald cut diamond may be the perfect choice for you.

Watch Emerald Diamonds in HD 360 Degrees.

Keep Points to Know

Buy an emerald cut diamond with a depth of 61-67%, a table percentage of 62-70%, and a length-to-width ratio of 1.4-1.5.
Avoid fluorescence in colorless diamonds, and ensure the stone comes with a GIA grading report.
Because emerald cut diamonds have open facets, prioritize the clarity grade to avoid visible inclusions.

Balancing the 4Cs

While prioritizing the 4Cs, consider an emerald cut diamond like this: example 1, VVS/D-E range for a pure investment-grade diamond in the highest quality range.
Consider an emerald cut like this: example 2, VS-F/G range to maximize quality without compromising carat weight.
If you are willing to compromise quality slightly to maximize the carat weight, consider an option like Example 3, VS-SI1/I-J range.
Finally, buyers can compromise on color entirely under the fourth scenario to maximize cut, clarity, and carat weight and get a big diamond such as this option: example 4, VVS/VS-K-M range.

emerald cut diamond depth and table

TOPLINE

Buy an emerald diamond with a depth of 59% to 69%, a table of 58% to 72%, and a length-to-width ratio of 1.4 to 1.5.
Prioritize the clarity grade of emerald cut diamonds as they have open facets.

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Emerald Cut Key Insights

Before buying emerald cut diamonds, consider the key factors regarding cut proportions, color, clarity, certification, fluorescence, and settings.

Shape Popularity	Emerald cut diamonds are among the most popular diamond shapes. They are different because of their classic and antique shape and have a step-cut with only as few as 49 facets. If you want elegance, go for an emerald cut diamond. In addition to square emerald cuts, a good square alternative to the emerald cut diamonds is the Asscher cut.
Cut	We recommend a depth of 59–69% and a table of 58–72%. For precise instructions, see the chart below.
L/W Ratio	While a length-to-width ratio of 1.3-1.55 is standard, we generally prefer the 1.4-1.5 range. See more below.
Color	D-F are colorless ranges, G offers great value, and H/I are exceptional budget options. See our chart below for comparison.
Clarity	Since emerald cut diamonds have open facets, prioritize their clarity with VS2/SI1 as the minimum acceptable grade. See more below.
Certification	We recommend AGS and GIA as the top grading labs for diamonds. Review the section below on how to read a grading report carefully.
Settings	From our experience, halo settings with round melees complement emerald cut diamonds beautifully. For reference, check our list of the top ten emerald cut engagement rings.
Best Places to Buy	Here is our list of the best places to buy diamonds. Additionally, lab-grown diamonds are a good option for buyers with a tight budget.

Emerald Cut Ideal Proportions

The chart provided below serves as a general guideline for evaluating the cut of an emerald cut diamond. Traditionally, a length-to-width ratio of 1.50 is considered the classic for a rectangular-shaped emerald cut diamond. However, in recent times, there has been a trend towards a more square shape, with a length-to-width ratio of 1.30.

emerald cut diamonds

Using James Allen's 3D Video Technology and comparing emerald cut diamonds with their 360-degree videos can be immensely helpful in determining how the following proportions and different length-to-width ratios affect a diamond's visual appearance. Compare several options with their search filter to get a good sense of what to prioritize regarding cut.

Refer to the chart below for precise proportions and the specific length-to-width ratio of these elegant diamonds.

Depth %

Poor/Fair: <52.5 or > 80 / 74.6 - 80

Good: 57 - 59 / 71- 74.5

Very Good: 58-61/67.4-70.1

Excellent: 61.3 - 67

Table %

Poor/Fair: <50 or >80/50-52.5 or 75.5-80

Good: 53-57/74

Very Good: 58-61/71

Excellent: 62-70

Culet

Poor/Fair: Very Large/Large

Good: Slightly large

Very Good: Medium/Very Small

Excellent: None

Girdle

Poor/Fair: Ex. Thin – Ex. Thick

Good: Very thin - thick

Very Good: Very thin - slightly thick

Excellent: Very thin - slightly thick

Square L/W Ratio

Poor/Fair: >1.09 /1.07-1.09

Good: 1.05-1.06

Very Good: 1.00-1.04

Excellent: 1.00-1.04

Rectangular L/W Ratio

Poor/Fair: >1.90 /1.81-1.90

Good: 1.20-1.29/1.63-1.80

Very Good: 1.30-1.38/1.51-1.70

Excellent: 1.39-1.50

Emerald Cut Diamond Shape Pattern

Best Color for Emerald Cut Diamonds

Like evaluating the color in other diamond shapes, the color in an emerald cut diamond is critical. The higher the color grade, the better. Given the price difference, many buyers prefer stones with warm colors over colorless ones.

Warmer colors refer to the near-colorless range of G-I color diamonds in the color spectrum, while the colorless ones refer to D-F color diamonds. The price premium for a warmer color grade emerald cut diamond is significantly lower. However, since the body of emerald cut diamonds is large and contains open facets, choosing a higher color grade is recommended.

Diamond Color Chart

For more detailed information selecting the best color for an emerald cut diamond, use the chart below based on carat weight while buying one:

< 0.50 Carat

Poor/Far: >M/ L-M

Good: I

Very Good: G-H

Excellent: D-G

0.51 – 1.0 Carat

Poor/Fair: J-K / >L

Good: I

Very Good: H

Excellent: D-G

1.0 – 2.0 Carat

Poor/Fair: H-I / >I

Good: J/I

Very Good: G-H

Excellent: D-F

>2.0 Carat

Poor/Fair: H-I / >I

Good: H-I

Very Good: F-G

Excellent: D-E

Florescence

Poor/Fair: Very Strong/Strong

Good: Medium

Very Good: Faint

Excellent: None

Best Clarity for Emerald Cut Diamonds

Since emerald cut diamonds have open facets, we recommend buying a slightly higher clarity stone. However, each of our customers has a unique standard for clarity and color. Some want flawless diamonds, while others are perfectly comfortable with inclusions if they are not noticeable to the naked eye.

GIA's clarity grading system is highly helpful in selecting the best clarity grade that will meet a buyer's particular requirements.

On the clarity scale, the VS2 range would be an outstanding balance of price and appearance in an emerald cut diamond. Review the chart below carefully for our recommended clarity grade for an emerald cut diamond based on its carat weight:

< 0.50 Carat

Poor/Far: >I1/ I1

Good: SI1-SI2

Very Good: SI1-SI2

Excellent: FL-VS1

0.51 – 1.0 Carat

Poor/Fair: I1-I3

Good: SI1-SI2

Very Good: VS2-SI1

Excellent: FL-VS1

1.0 – 2.0 Carat

Poor/Fair: I1 / >I1

Good: SI2

Very Good: SI1/ VS2

Excellent: FL-VS1

>2.0 Carat

Poor/Fair: I3/II1

Good: SI2

Very Good: SI1/VS2

Excellent: FL-VS1

Emerald Cut Diamond Certification

In addition to the well-known 4Cs, it is imperative for buyers to be familiar with the following key aspects of an emerald cut diamond grading report or certificate, as highlighted in the image below.

emerald cut grading report

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Measurements: This is significant as it provides the buyer with information about the surface size of the diamond, indicating how large the diamond will appear in millimeters. Additionally, it will offer you the length-to-width ratio by dividing the length by the width (in the above case, it is 8.07 / 5.88 = 1.38).

Fluorescence: This should be regarded as the fifth C. Considering that the color is G, avoiding fluorescence is the optimal choice in this specific example. However, medium blue fluorescence is not as concerning as strong blue fluorescence.

Proportions: This chart is crucial for assessing a diamond's cut. Specifically, pay attention to the table percentage (62.6% in the example—excellent), depth percentage (67%—excellent), girdle (medium—excellent), and culet (none—excellent).

Clarity Characteristics: This section will indicate the types of inclusions and their respective locations. It can help buyers avoid diamonds with visible inclusions at the center. These details are also useful for correlating the report with the diamond, as these inclusions serve as the diamond's unique birthmarks.

Inscriptions/Comments: This section will present factors related to clarity and indicate whether a diamond has undergone clarity enhancement using methods like laser drilling or color enhancement, among others. Additionally, pay attention to comments such as "clarity grade based on clouds," a concerning indicator within clarity grades of VS2 and below. The laser inscription of the report number on the girdle is positioned above the comments section, offering an optional service for added verification.

Best Budget Options

The following options regarding carat weight, cut, color, and clarity are suggested for people with budget constraints.

Emerald Shaped Halo Engagement Ring Custom Designed by Petra Gems

Excellent Choice

At Least 1.2 Carats in Weight
Very Good to Excellent Polish and Symmetry
G or above in Color
SI1 or above in Clarity
No Fluorescence
Length/width ratios: 0.95 - 1.05 for a square or 1.5 to 1.60 for a rectangular shape

Very Good Choice

At Least 1.00 Carat in Weight
Good to Excellent Polish and Symmetry
H or above in Color
SI1 or above in Clarity
None, faint or medium blue Fluorescence
Length/width ratios: 0.95-1.05 for a square or 1.45 to 1.65 for a rectangular shape

Good Choice

At least 0.90 Carats in Weight
Good to Very Good Polish and Symmetry
I or above in Color
SI1 or above in Clarity
None, faint or medium blue Fluorescence
Length/width ratios: 0.95-1.05 for a square or 1.4-to 1.68 for a rectangular shape

Helpful References

Everything You Need To Know About Emerald Cut Diamonds (Link)
Sotheby’s Perfect 100-Carat Emerald Cut Diamond Could Fetch $25 Million (Link)
All Of Jennifer Lopez's Engagement Rings, Ranked (Link)