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Radiant Cut Diamonds

Radiant Cut Diamonds

If any diamond shape could evoke the golden age of Hollywood, it would be the Radiant Cut.

Outline Usually rectangular but can be square; clipped corners
Cutting Style Brilliantized Step Cut
Description A luxuriously sparkling stone with a complex layered look
No. of Facets 70
Ideal L/W Ratio 1.10 - 1.50


This is a stone that oozes glamour: think Fred and Ginger, Greta Garbo, and Marilyn Monroe. Its tightly patterned facets and truncated corners form a luxurious diamond pillow with sparkle enough to rival the Round Brilliant

Often rectangular but also popular as a square, the Radiant Cut offers a uniquely different stone to those willing to see past the popularity of the Princess Cut. As an engagement ring, there is perhaps no shape that looks more extravagant or lavish. The Radiant Cut is sumptuousness with a capital $.

We Say
Fancy shaped diamonds with low colour grades offer exceptional value. However, bear in mind colour may be slightly intensified in the corners so we recommend a G colour grade or higher.


A Radiant Cut diamond usually has 70 facets - 25 on the crown, 8 on the girdle, and 37 on the pavilion. On GIA grading reports it is often referred to as a “cut-cornered, rectangular (or square), modified brilliant”.

A loose radiant shape diamond vectorA loose radiant shape diamond vector

It’s a common misconception that a Radiant Cut is simply a Princess Cut with the corners cut off. However, the two are very different. The Princess Cut’s contrasting linear reflections complement its straight edges and sharp corners whereas in a Radiant Cut, which was designed by superimposing a round brilliant cut over a rectangular outline, the reflections are circular in nature. This allows light to enter the diamond from many angles resulting in reflections with a many-layered effect. 

Because of its high number of facets, a Radiant Cut diamond is more forgiving of flaws and weaknesses than our other rectangular shape, the Emerald Cut giving you the flexibility to drop a cut or clarity grade in favour of better colour or carat weight.


Currently, there aren't any universally accepted standards for grading the cut of Radiant Cut diamonds so certifying laboratories don’t do it. Instead, it’s down to individual retailers to evaluate the quality of the cut for this shapes.

We've developed our own criteria to provide consistent cut grading for all the Radiant Cut diamonds we offer. These take into account factors such as table and depth percentage, polish and symmetry, and length to width ratio.

Refer to the table below to see how we grade Radiant Cut diamonds.

  Excellent Very Good Good Fair Poor
Table % 58%-65% 56%-70% 54%-75% 53%-79% <53% or >79%
Depth % 62%-68% 58%-70% 57%-75% 56%-80% <56% or >80%
Polish / Symmetry Good to Excellent Fair to Excellent Poor to Excellent
Ratio (L/W) 1.00-1.50 1.00-1.60 1.00-1.70 <1.00 or >1.70


The Radiant Cut first appeared in 1977 as the culmination of 30 years research by Henry Grossbard, a native of Austria who became a master diamond cutter in New York. His dream was to develop a cut that “…retained the shape of a traditional emerald cut, but infused it with the brilliance people expected of their diamonds.”

Before the appearance of the Radiant Cut, rectangular or square diamonds were step cut – resulting in long, rectangular facets that couldn't compete with the brilliance and fire of round edged diamonds with triangular and kite-shaped facets. Grossbard’s technique combined the two cutting styles in a hybrid “brilliantized step cut” to create diamonds with the elegance of an emerald cut and the brilliance of a round stone.

The Radiant Cut was one of the first diamond cuts to be granted a patent but this has since expired making Radiant Cuts widely available at reasonable prices.

The Radiant Cut was a popular forerunner to the Princess Cut but has now been surpassed in popularity by its sharp-cornered cousin. 


Solitaire Diamond Engagement Ring in 18K Yellow Gold Diamond Set Engagement Ring in Platinum

Gorgeous, romantic, an aspiring star with class and extravagance – that describes both the Radiant Cut and the woman its designed for. This shape suits someone who loves a bit of drama and glamour, and who isn’t afraid of the extra attention it will draw – in fact, she’ll thrive on it.

Length to Width Ratio

The Radiant Cut shines as both square and rectangle. For a square, look for a length to width ratio of between 1.00 and 1.05 and for a more rectangular shape, opt for a ratio between 1.10 and 1.50. 

The Radiant Cut diamond better suits medium to long fingers. However, for short fingers, a rectangular version with a ratio of 1.2 or higher will have a lengthening effect.


A Radiant Cut is stunning on its own as either a ring or a pendant, or equally beautiful set with either baguette or round side diamonds.

Because it’s a quadrilateral, a Radiant Cut diamond requires a minimum of a four-prong setting.

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