Asscher Cut Diamonds | In-Depth Guide, Proportions, L/W Ratio

Sharif Khan
Sharif Khan
Last Updated    EST 
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Named after the Royal Asscher Diamond Company, the Asscher cut was considered a revolutionary concept when it was created. While its popularity faded in the last century, Asscher cut diamonds are now considered a popular diamond shape. The demand for this shape particularly increased in early 2002, mostly because cut modifications gave the diamond more brilliance.

The open facets of Asscher cut diamonds create seemingly endless hallways lined with reflective mirrors, radiating elegant fire and brilliance. The modern Asscher cut diamond shares similar features with a square emerald cut diamond, with a smaller table, a higher crown, and larger step facets. Properly positioned pavilion facets create lovely concentric squares in the Asscher cut diamond. Besides the square shape of the Asscher cut, cropped corners give the cut a unique octagonal shape. When placed in a four-prong setting, the Asscher cut will maintain its shape within a square silhouette.

Key Points to Know

  • Cut: Ideal Depth: 61-67%, Table: 62-70%, Length-to-Width Ratio: 1-1.05.
  • Color: Ideal choices include D-F colorless diamonds, G provides great value, and H/I is an exceptional budget option.
  • Clarity: Opt for a high clarity grade in Asscher cuts, considering their open facets, with a minimum VS2 grade.
  • Fluorescence: Avoid it in colorless diamonds while being flexible in H or lower color grades.
  • Certification: Buy an Asscher cut diamond with a full GIA grading report.

The 4Cs can be prioritized in four primary ways while buying an Asscher cut diamond. To prioritize quality, consider an Asscher cut like this: Example 1, VVS/D-E range; to maximize size and quality, consider this: Example 2, VS/F-G range; to get the largest possible stone while still maintaining quality, consider this: Example 3, SI1/H-I range; and to compromise on one C and maximize on other 3Cs, buy a lower color grade Asscher cut diamond with exceptional quality and cut like this: Example 4, VVS-VS/J-M range.

depth and table for asscher cut diamonds

For assistance with sourcing an ideal cut Asscher cut diamond, contact us.

Assess the quality of Asscher cut diamonds with exceptional 40X Magnified Videos.

Asscher Cut Diamond Highlights

ShapeAsscher shaped diamonds are among the most popular diamond shapes. The Asscher cut is an ideal choice for lovers of a step and antique shape. 
While evaluating the cut, a depth of 60% to 68% and a table of 61% to 71% are recommended for the Asscher shaped diamonds, with a tolerance of 1-2% (up or down). See our proportions chart below for more insights.
D-F colors are considered colorless, while "G" is also a great color. Moreover, "H" and I colors are great budget options.
L/W Ratio
A length-to-width ratio of 1 to 1.05 is ideal. See more below.
Flawless to VVS clarity grades are exceptional. VS1 and VS2 are also safe grades for Asscher cut. When considering SI1 and SI2 clarity grades, carefully evaluate the diamonds to ensure the stone is eye clean. Given the open facets, we recommend buying a high clarity grade asscher cut diamond.
Avoid fluorescence in the "D" to "G" color range; up to medium blue is safe in "H", "I", and lower color grades.
Buy a GIA or AGS-graded Asscher cut diamond. Read our instructions on how to read a grading report below carefully.
Both classic and modern settings suits Asscher cut diamonds nicely. Consider halo settings for smaller Asscher cut diamonds. Here is a list of our top Asscher cut engagement rings.
Best Places 
Here is a list of our best places to buy diamonds online.

Ideal Asscher Cut Proportions

The chart below serves as a general guideline when evaluating the cut of an Asscher cut diamond. For example, a 1.00 length-to-width ratio is considered classic for a square shape in the Asscher cut. While slightly rectangular shapes exist among Asscher cut diamonds, a ratio of 1.05 or less will appear square to the naked eye. 

Depth %

Poor/Far: <52 or >80 / 52-80

Good: 57-59 / 71-74.5

Very Good: 58.8-70/67-70.1

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

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

asscher cut diamond proportions

Color in Asscher Cut Diamonds

Color is a critical factor in Asscher cut diamonds. Like other diamond shapes, color in an Asscher cut diamond is subjective. Our experience indicates that many buyers prefer warmer colors over cooler ones due to affordability. In the color spectrum, the former (warmer colors) refer to G-I diamonds, whereas the latter (cooler colors) refer to D-F diamonds. On the positive side, the price premium for H and I color grade Asscher cut diamonds is significantly lower than for D-E color diamonds.

diamond color chart

Fluorescence in a diamond is often a negative factor. However, it can be helpful to warmer color diamonds because blue is a complementary color to yellow, making a diamond with a yellow hue appear whiter than its actual color grade. 

For more detailed information on the color of an Asscher cut diamond, use the table below.

< 0.50 Carat

Poor/Far: >M/ L-M

Good: J-K

Very Good: H-I

Excellent: D-G

0.51 – 1.0 Carat

Poor/Fair: J-K / >L

Good: I-J

Very Good: H

Excellent: D-G

1.0 – 2.0 Carat

Poor/Fair: H-I / >I

Good: G

Very Good: D-F

Excellent: D-F

>2.0 Carat

Poor/Fair: H-I / >I

Good: G-H

Very Good: F

Excellent: E-F


Poor/Fair: Very/Strong

Good: Medium

Very Good: Faint

Excellent: None

Clarity in Asscher Diamonds

Since Asscher cut diamonds have open facets, we recommend buying a slightly higher clarity Asscher cut diamond. Our customers have a unique standard for clarity and color; some want flawless diamonds, while others are comfortable with inclusions if they are not noticeable to the naked eye. Select the clarity grade of an Asscher cut diamond based on our guidance outlined below.

Diamond Clarity Chart

SI1 would have an outstanding balance of price and appearance in an Asscher cut. However, we recommend VS2 or above in 1.5+ carat diamonds because Asscher cut diamonds have open facets. 

< 0.50 Carat

Poor/Far: >I1/ I1

Good: SI2

Very Good: SI1

Excellent: FL-VS2


0.51 – 1.0 Carat

Poor/Fair: SI2-I2 / > SI2

Good: SI1

Very Good: VS2-SI1

Excellent: FL-VS1

1.0 – 2.0 Carat

Poor/Fair: SI2-I1 / >I1

Good: SI1

Very Good: VS2

Excellent: FL-VS1

>2.0 Carat

Poor/Fair: SI2 / >SI2

Good: SI1

Very Good: VS1-VS2

Excellent: FL-WS2

How to Read the Grading Report

As the image below underscores, buyers must acquaint themselves with the subsequent pivotal facets of an asscher cut diamond grading report or certificate in addition to the well-known 4Cs.

GIA asscher cut diamond certificate

Watch the HD video of this diamond.

Measurements: This is very significant as it furnishes the buyer with information regarding the diamond's surface size (indicating its apparent size in millimeters). Moreover, it provides the length-to-width ratio by dividing the length by the width (in this case, it calculates to 6.36/6.35=1).

Fluorescence: This aspect ought to be considered the fifth C. Given that the color is G, none or faint fluorescence is the best choice in this specific example. Nevertheless, moderate blue fluorescence is not as concerning as strong blue fluorescence.

Comments: This section will exhibit clarity-related factors and illuminate whether a diamond has undergone clarity enhancement, employing laser drilling or color enhancement methods. Additionally, pay heed to comments like "clarity grade based on clouds," which is a troubling indicator within clarity grades of VS2 and below. The laser inscription of the report number on the girdle is positioned above the comments section, providing an optional service for added verification.

Proportions: This chart assumes the utmost importance in evaluating the cut of a diamond. Concretely, focus on the table percentage (64% in the example - excellent), depth percentage (68.2% - excellent), girdle (medium to slightly thick - excellent), and culet (none - excellent).

Clarity Characteristics: This section will denote the types of inclusions and their respective locations. It can aid buyers in evading diamonds with noticeable inclusions at the center. Furthermore, these details prove valuable for establishing a connection between the report and the diamond, as these inclusions function as the diamond's unique birthmarks.

Recommended Budget Choices

Below are general guidelines for navigating the 4Cs within a tight budget. For more information, read this article on how to prioritize the 4Cs.

Asscher Shaped Split Band Engagement Ring (Watch in HD

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: 1-1.04

Very Good Choice

  • At least 1 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: 1-1.04

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: 1-1.04

While working with a tight budget, consider lab-grown diamonds as an alternative. Besides James Allen, Blue Nile is an excellent company for buying lab diamonds.