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What is a Radiant Cut Diamond?

by Willyou.net * May 10, 2021

The Radiant cut diamond is a non-traditional, square diamond, a combination of the princess and cushion cuts. It is the first square cut to have the brilliant-cut facet pattern applied to its crown and pavilion. It’s a unique cut made up of 70 facets with soft corners. 

Radiant cut diamond

Radiant Cut Diamond History

The Radiant cut was first designed in 1977 by Henry Grossbard of the Radiant Cut Diamond Company. He invented a hybrid cutting style, revolutionizing the step-cut diamond and changing the way it was developed. It then became a popular cut in the 1980’s and in 2002, RCDC launched their ‘Original Radiant Cut’ diamond brand..

The Radiant cut is one of the most popular diamond cuts because of its versatility and brilliance. Celebrities such as Jennifer Lopez, Megan Fox and Kelly Clarkson all adorn Radiant cut engagement rings on their fingers. 

Choosing a Radiant Cut Diamond

The rectangular radiant cut is a great option for those who likes the shape of an emerald cut, but are looking for something with more brilliance like that of a round. 

Choosing a Radiant cut setting is a personal choice, but there are settings that work especially well with the cut. A solitaire setting, especially with prongs, looks stunning with the Radiant cut as well as Radiant cut engagement ring with a diamond halo. 

Square Radiant Cut Diamond Size Chart

A Radiant cut diamond has an approximate millimeter size corresponding to its weight in carats. See the chart below for size examples. 

0.25ct0.50ct0.75ct1.00ct1.50ct2.00ct3.00ct4.00ct5.00ct
3.5 x 3 mm5 x 4.5 mm5.5 x 5 mm6 x 5.5 mm7 x 6 mm7.5 x 7 mm8.5 x 7.5 mm9.5 x 8.5 mm10 x 9 mm

The following cut, color and clarity guides should be taken into consideration when choosing a Radiant cut diamond: 

Radiant Cut Diamond Length-to-Width Guide

A classic Rectangular Radiant has a length-to-width ratio between 1.22 – 1.32 and a Square Radiant classic length-to-width ratio is 1.00.

ExcellentVery GoodGoodFairPoor
Square1.00 – 1.0291.03 – 1.0391.04 – 1.051.06 – 1.08 >1.09
Rectangular1.22 – 1.321.15 – 1.21
or
1.33 – 1.39
1.10 – 1.14
or
1.40 – 1.45
1.08 – 1.09
or
1.46 – 1.50
<1.08
or
>1.50

Square Radiant Cut Diamond Guide – Cut

ExcellentVery GoodGoodFairPoor
Table %61 – 69.957 – 60.9
or
70 – 72.9
54 – 56.9
or
73 – 74.9
51 – 53.9 or
75 – 79.9
<50.9
or
>80
Depth %61 – 67.959 – 60.9 or
68 – 69.9
57 – 58.9 or
70 – 73.9
54 – 56.9 or
74 – 79.9
<53.9
or
80
GirdleVery Thin
or Slightly Thick
Very Thin
or
Thick
Very Thin
or
Very Thick
Extremely Thin
or
Extremely
Thick
CuletNoneVery SmallSmallMedium>Large

Radiant Cut Diamond Symmetry, Polish, Cut and Fluorescence Guide

Our experience suggests that Cut, Symmetry, Polish, and Fluorescence contributes to a diamond’s brilliance so that most buyers will choose Excellent – Very Good and Fluorescence None – Faint.

ExcellentVery GoodGoodFairFair – Poor
CutExcellentVery GoodGoodFair – Poor
PolishExcellentVery GoodGoodFair – Poor
SymmetryExcellentVery GoodGoodFair – Poor
Fluorescence NoneFaintMediumStrong – Very Strong

Square Radiant Cut Diamond Color Guide

Most buyers prefer size over color hue and will buy a diamond of G color.

ExcellentVery GoodGoodFairPoor
< 0.50 ct.D – GH – IJ – KL – M > N
0.51 – 1.00 ct.D – F G – HI – JK> L
1.00 – 2.00 ct.D – FG – HI – JK> J
>2.00 ct.D – FG – HI – JK> J

Square Radiant Cut Diamond Clarity Guide

Most buyers prefer size over clarity cleanse and will buy a diamond of VS2 – SI1 Clarity.

ExcellentVery GoodGoodFairPoor
< 0.50 ct.FL – VS2SI1 – SI2I1I2> I2
0.51 – 1.00 ct.FL – VS1VS2 – SI1SI2I1 – I2 > I2
1.00 – 2.00 ct.FL – VS1VS2 – SI1SI2I1> I1
>2.00 ct.FL – VS1VS2 – SI1SI2I1> I1

Rectangular Radiant Cut Diamond Guide – Cut

ExcellentVery GoodGoodFairPoor
Table %60 – 66.958 – 59.9
or
67 – 70.9
54 – 57.9
or
71 – 74.9
51 – 53.9 or
75 – 79.9
<50.9
or
>80
Depth %63 – 67.959 – 62.9 or
68 – 69.9
57 – 58.9 or
70 – 74.9
54 – 56.9 or
75 – 79.9
<53.9
or
80
GirdleVery Thin
or Slightly Thick
Very Thin
or
Thick
Very Thin
or
Very Thick
Extremely Thin
or
Extremely
Thick
CuletNoneVery SmallSmallMedium>Large

Rectangular Radiant Cut Diamond Color Guide

Most buyers prefer size over color hue and will buy a diamond of G color.

ExcellentVery GoodGoodFairPoor
< 0.50 ct.D – GH – IJ – KL – M > N
0.51 – 1.00 ct.D – F G – HI – JK> L
1.00 – 2.00 ct.D – FG – HI – JK> J
>2.00 ct.D – FG – HI – JK> J

Rectangular Radiant Cut Diamond Symmetry, Polish, Cut and Fluorescence Guide

ExcellentVery GoodGoodFairPoor
CutExcellentVery GoodGoodFair – Poor
PolishExcellentVery GoodGoodFair – Poor
SymmetryExcellentVery GoodGoodFair – Poor
Fluorescence NoneFaintMediumStrong – Very Strong

Rectangular Radiant Cut Diamond Clarity Guide

Most buyers prefer size over clarity cleanse and will buy a diamond of VS2 – SI1 Clarity.

ExcellentVery GoodGoodFairPoor
< 0.50 ct.FL – VS2SI1 – SI2I1I2> I2
0.51 – 1.00 ct.FL – VS1VS2 – SI1SI2I1 – I2 > I2
1.00 – 2.00 ct.FL – VS1VS2 – SI1SI2I1> I1
>2.00 ct.FL – VS1VS2 – SI1SI2I1> I1

Radiant Cut Diamonds Pros and Cons

There are pros and cons with every type of cut, including the Radiant cut. An advantage of the Radiant cut is that it hides the blemishes of the stone better than most cuts. The Radiant has a special talent in hiding them. It is also very versatile, allowing for the cut to pair well with almost any style. 

A disadvantage of the Radiant is its bow-tie effect. With more rectangular cuts, the Radiant shape can produce an area of reduced color in the center of the gem, resembling a bow tie. 

Hand-Selected Radiant Cut Diamonds

View More Radiant Cut Diamonds here