Emerald Cut Diamonds: In-Depth Guide, Proportions, Ratios, Charts

Emerald Cut Diamonds: In-Depth Guide, Proportions, Ratios, Charts

Emerald Cut Diamonds: In-Depth Guide, Proportions, Ratios, Charts

Posted by Sharif Khan on 23rd Oct 2022

Emerald Cut Diamonds

Emerald Cut Diamonds Ratio

The cutting of diamonds into an emerald shape dates to the 13-14th century, when diamonds began to make their way into popular culture. The modern emerald cut diamond has 48 facets. Twenty-five are spread roughly across the crown, 25 across the pavilion, and eight across the girdle, with three rows each of bottom and top steps. These luminous gems feature step-cut (or trap-cut) because they have rows of facets different from other fancy-cut shapes. These facets are arranged in a rectilinear style parallel to the girdle, typically in a staircase form, hence the name step-cut.

Usually, the corners of diamonds are the weakest points for a typical stone, but emerald-cut diamonds beautifully address this concern. In addition, the emerald-cut diamond features a keel running through the pavilion terminus that is unavailable in other diamond cuts.

During the Art Deco period, many antique jewelry pieces featured step-cut styles, which is why diamond lovers today are keen to recapture the aesthetics of that time. An emerald cut diamond is the right choice if you love classic styles typically found in antique jewelry.

Key Takeaways

  • 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 48 facets. If you want elegance, go for an emerald-cut diamond.
  • Since emerald cut diamonds have open facets on the table, prioritize their clarity with VS2/SI1 as the minimum acceptable grade.
  • While a length-to-width ratio of 1.3-1.55 is standard, we generally prefer the 1.4-1.5 range. Please make sure that you know what you like!
  • In terms of cut, a depth of 59–69% and a table of 58–72% are recommended. See the chart below for accurate numbers.
  • We recommend AGS and GIA as the top labs, though you should try to buy a GIA-graded diamond.
  • In prioritizing the 4Cs, consider an option like this (example 1). If you want a pure investment-grade diamond in the high-quality range. If you want to maximize quality and carat weight, consider something like this (option 2). It will be a good option if you do not mind slightly compromising quality to maximize the size (example 3). Finally, another option could be to compromise on color to maximize cut, clarity, and carat weight if the budget is an issue and you want a big diamond (example 4).
  • A good square alternative to the emerald cut diamonds is the Asscher Cut Diamonds.
  • Here is the list of our top websites for buying diamonds and engagement rings online to consider. Lab-grown diamonds are also a good option for buyers with low budgets. 
  • Here is a list of our top ten emerald cut diamonds engagement rings.

Analyzing the Cut in Emerald Diamonds

We find it very useful to play with James Allen's 3D Video Technology and compare the 360-degree videos of different emerald-cut diamonds to figure out how the following proportions and different length-to-width ratios affect the visual appearance of a stone. Try to play with their filter to get a good sense of what to prioritize in terms of cut.

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

Length to Width Ratio for Square Shape

Poor/Fair: >1.09 /1.07-1.09

Good: 1.05-1.06

Very Good: 1.00-1.04

Excellent: 1.00-1.04

Length to Width Ratio for Rectangular Shape

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

James Allen

The chart above serves as a general guideline when evaluating the cut of an emerald-cut diamond. The length-to-width ratio of 1.50 is considered the classic cut for a rectangular-shaped emerald cut diamond. However, the recent trend is towards a square shape with a ratio of 1.30. Consult Petra Gems for precise measurements and the length-to-width ratio of these elegant diamonds.

Evaluating Color

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 lower 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.

For more detailed information on the color of the emerald cut diamond, use the table below:

< 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

Choosing Clarity

Given that 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. The GIA provides excellent help with their clarity grades. You can use it to choose an emerald-cut diamond that will meet your standards.

An SI1 would be an outstanding balance of price and appearance in an emerald cut. You can also consider buying VS2 for a comparable choice.

< 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

Budget Options

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

Excellent Choice:

  • At least 1.0 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 0.90 carats 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 0.80 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