Emerald Cut Diamonds In-Depth Guide, Proportions, L/W Ratios

Sharif Khan
Sharif Khan
Last Updated    EST 

Before buying emerald cut diamonds, here are the key important factors to consider with regards to cut proportions, color, clarity, certificaiton, fluoresence, 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: In terms of cut, a depth of 59–69% and a table of 58–72% are recommended. See the chart below for precise instructions.
  • 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 cololess 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.
  • Certificaiton: We recommend AGS and GIA as the top grading labs for diamonds. Review the section on how to read a grading report below carefully. 
  • Settings: From our experience, halo settings with round melees complement emerald cut diamonds beautifully. For reference, check our list of top ten emerald cut engagement rings.
  • Best Places: Here is our list of best places to buy diamonds. Additionally, lab-grown diamonds are a good option for buyers with a tight budget.
  • Balacing 4Cs: While prioritizing the 4Cs, consider an option like this (example 1, VVS-E/D range) for a pure investment-grade diamond in the highest quality range. Consider a diamond like this (option 2, H-G/VS range) to maximize quality without compromising carat weight. If you do not mind compromising quality slightly to maximize the carat weight, consider an option like this (example 3, I-J/VS range). Finally, under option four, a buyer can compromise on color to maximize cut, clarity, and carat weight to get a big diamond (example 4, K-L/VVS range).

emerald cut diamond depth and table

Search & Watch Emerald Diamonds in HD 360 Degrees.

Emerald Cut Diamonds Background

The cutting of diamonds into an emerald shape dates back to the 13th and 14th centuries when diamonds started gaining popularity in culture. The modern emerald cut diamond has 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. These brilliant gems feature a step-cut (or trap-cut) with facets arranged in a rectilinear style parallel to the girdle, creating a staircase-like appearance, hence the name step-cut.

Typically, the corners of diamonds are the weakest points for a regular stone, but emerald cut diamonds beautifully address this concern. The emerald cut diamond also features a keel running through the pavilion terminus, a unique characteristic not found in other diamond cuts.

During the Art Deco period, many antique jewelry pieces showcased step-cut styles, which is why diamond enthusiasts today are eager to recapture the aesthetics of that time. If you love classic styles commonly found in antique jewelry, an emerald cut diamond is the perfect choice.

Ideal Proportions for Emerald Cut Diamonds

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

For precise proportions and the specific length-to-width ratio of these elegant diamonds, refer to the chart below. 

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


Poor/Fair: Very Large/Large

Good: Slightly large

Very Good: Medium/Very Small

Excellent: None


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

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 the visual appearance of a diamond. Compare several options with their search filter to get a good sense of what to prioritize in terms of cut.

Emerald Cut Diamond Shape Pattern

Color in 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. In our experience, many buyers prefer stones with warm colors over colorless ones, given the price difference.

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. Therefore, the price premium for a warmer color grade emerald cut diamond would be significantly lower. However, since the body of emerald cut diamonds is large and contains open facets, choosing a higher color grade is recommended when buying an emerald cut diamond.

Diamond Color Chart

For more detailed information on the color of the emerald cut diamond, use the chart below based on carat weight:

< 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


Poor/Fair: Very Strong/Strong

Good: Medium 

Very Good: Faint

Excellent: None

Clarity in 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 your standards.

Diamond Clarity Chart

An VS2 would be an outstanding balance of price and appearance in an emerald cut. Check 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

How to Read Emerald Cut GIA Report

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

Watch HD Video of this Diamond.

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. In this specific example, considering that the color is G, avoiding fluorescence is the optimal choice. However, medium blue fluorescence is not as concerning as strong blue fluorescence.

Proportions: This chart is the most crucial for assessing the cut of a diamond. 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 will also 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," which is 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.

Good Emerald Cut Budget Options

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

emerald diamond engagement ring

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 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 square or 1.4-to 1.68 for a rectangular shape

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