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Radiant Cut Diamonds Assessment Chart Guide In-depth Information

Posted by Sear R. on

Evaluating Radiant Cut Diamonds

                                                 Square vs rectangular radiant cut  

Be sure to check out our diamond filter to compare actual prices. 

Radiant Cut diamond is one of our favorite diamond shapes. The 70 facets in a radiant cut diamond allows it to emanate a tremendous amount of shine. Radiant cut diamond is a vibrant and exuberant square/rectangular diamond that has complete brilliant-cut facet pattern applied to its crown and pavilion. Radiant cut diamond is also an excellent reflector of light - this is why it served as an alternative to the emerald cut diamond when it was invented. Since 1970’s, radiant cut diamond has been a popular choice, and credit goes to Henry Grossbard – the mastermind behind the shape of radiant cut diamond.

Analyzing Cut

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
  • Culet
  • Poor/Fair: Large/Very Large
  • Good: Medium
  • Very Good: None/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
  • Length to Width Ratio for Square Cut
  • 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 Cut
  • Poor/Fair: <1.08 or >1.41/1.07-1.08
  • Good: 1.09-1.13/1.37-1.41
  • Very Good: 1.14-1.20/1.32-1.36
  • Excellent: 1.20-1.31
  • The chart above serves as a general guideline when evaluating the cut of a radiant diamond. The length to width ratio of 1.00-1.04/1.20-1.31 is considered the classic cut for both square and rectangular shape of radiant cut diamond, but the personal preference could override that. Consider the radiant cut diamond if you appreciate the sophistication of emerald diamond and the fire of a round diamond; it would be a perfect combination of a round and an emerald diamond in terms of fire and sophistication. You can also obtain a perfect combination between the cushion and princess cut if you look at its cropped corner square shape. That nice bridge between the cushion and princess cut makes it look beautiful set with either round or square corners.

    Evaluating Color

    Just like evaluating the color in other diamond shapes, color in a radiant cut diamond is critical. The higher the color grade, the better. In our experience, many buyers prefer the warmer colors over the colorless colors given the difference in price. In the color spectrum, the warmer colors refer to the near colorless range of G-I color diamonds while the colorless colors refer to D-F color diamonds. The price premium for a lower color grade radiant cut diamond would be significantly lower. 

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

    < 0.50 Carat
  • Poor/Far: >M/ L-M
  • Good: I-K
  • Very Good: G-I
  • 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: J-K / >I
  • Good: H-I
  • Very Good: G
  • Excellent: D-F
  • >2.0 Carat
  • Poor/Fair: I-K / >I
  • Good: I
  • Very Good: G-H
  • Excellent: D-F
  • Fluorescence
  • Poor/Fair: Very Strong
  • Good: Strong 
  • Very Good: Medium Blue/Faint/None
  • Excellent: None
  • Choosing Clarity

    Choosing the kind of clarity is subjective in a radiant cut diamond. Choose a radiant cut diamond that meets your standards in terms of clarity. Each of our customers has a unique standard for clarity and color. Some of our customers want a flawless diamond while others are perfectly comfortable with a slight inclusion as long as it is not easily noticed. In our experience, considering any clarity above SI2 (GIA standards) would be perfectly fine!

    < 0.50 Carat
  • Poor/Far: I2 / >I2
  • Good: I1-I2
  • Very Good: SI1-SI2
  • Excellent: FL-VS2
  • 0.51 – 1.0 Carat
  • Poor/Fair: I2 / >I2
  • Good: SI2
  • Very Good: SI1-SI2
  • Excellent: FL-VS2
  • 1.0 – 2.0 Carat
  • Poor/Fair: SI2-I1 / >I1
  • Good: SI1-SI2
  • Very Good: WS2-VS2
  • Excellent: FL-VS1
  • >2.0 Carat
  • Poor/Fair: >SI2
  • Good: SI1-SI2
  • Very Good: VS1-SI1
  • Excellent: FL-WS2
  • Suggested carat weight, cut, color and clarity of Radiant Cut Diamond 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 Florescence
    • Length/width ratios: 1.0-1.04 for a square or 1.20-1.35 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 florescence
    • Length/width ratios: 1.0-1.04 for a square or 1.20-1.35 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 florescence
    • Length/width ratios: 1.0-1.04 for a square or 1.20-1.35 for a rectangular shape

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