The radiant cut diamond is the first square cut (the second being the princess) to have a complete brilliant-cut facet pattern applied to both the crown and pavilion, creating a vibrant and lively square diamond.
First popular in the 1980’s, the cropped corner square shape of the radiant is a nice bridge between a cushion and a princess cut, and for that reason looks beautiful set with both rounded or square cornered diamonds.
In longer (more rectangular) radiant cut diamonds, a bow-tie effect is more likely (although not as common as in oval, marquise, and pear cuts), varying from near invisible to severe. The visibility of a bow-tie effect cannot be ascertained by reviewing the diamond certificate or dimensions, but only upon visual inspection.
There are diverse preferences when it comes to shape in radiant cut diamonds, from a perfectly square 1.00 length to width ratio (any ratio of 1.05 or less will appear square to the naked eye), to a more traditional rectangle.
The rectangular radiant cut is an excellent option for buyers who like the emerald cut shape, but want something with the brilliance of a round. For an 8 carat diamond, a rectangle is often though to make the finger look longer and more elegant.
The square radiant looks very similar to a princess cut, but with cropped corners. Once set, a square radiant and a princess look virtually identical, since the prongs cover the corners.
8 carat radiant cut guide
As a brilliant cut, the proportions of your diamond are all-important to ensure that it sparkles brilliantly.
You may find if you are looking at 8 carat radiant cut diamonds that the stone itself has been cut to maximise the carat weight, rather than to optimise light return.
If this is the case, you may find that the diamond appears dull in all but the brightest light. We always recommend that you select ‘ideal’ proportions if possible, to ensure that your diamond is not only impressive in size, but also in sparkle.
| IDEAL | EXCELLENT | VERY GOOD | GOOD | FAIR | POOR | |
|---|---|---|---|---|---|---|
| TABLE % | 60 – 60.5 | 61 – 69 | 57 – 60 or 70 – 72 | 54 – 56 or 73 – 74 | 51 – 53 or 75 – 79 | < 51 or > 79 |
| DEPTH % | 60 – 65 | 61 – 67 | 59 – 60.9 or 67.1 – 70 | 57 – 58.9 or 70.1 – 74 | 54 – 56.9 or 74.1 – 79 | < 54 or > 79 |
| GIRDLE | Very Thin – Slightly Thick | Very Thin to Thick | Very Thin to Very Thick | Extra Thin to Extra Thick | ||
| CULET | None | Very Small | Small | Medium | > Medium | |
| CROWN HEIGHT % | 12 – 15% | 11 – 16% | 9 – 16.5% | 7 – 18% | 6 – 20.5% | < 6% or > 20.5% |
While the priority that you place on cut quality is up to you, if you are making a significant investment in an 8 carat diamond ring, we recommend that you choose as close to ‘Ideal’ as possible.
8 carat radiant cut length-width guide
Which of these you choose is down to personal preference, but we recommend that you try to view a selection of diamonds to see what you like.
| IDEAL | EXCELLENT | VERY GOOD | GOOD | FAIR | POOR | |
|---|---|---|---|---|---|---|
| SQUARE | 1.00 – 1.03 | 1.04 – 1.05 | 1.06 – 1.08 | > 1.08 | ||
| RECTANGLE | 1.50 – 1.75 | 1.20 – 1.30 | 1.15 – 1.19 or 1.31 – 1.35 | 1.10 – 1.14 or 1.36 – 1.40 | 1.08 – 1.09 or 1.41 – 1.50 | < 1.08 or > 1.50 |
8 carat radiant cut color
Most jewelers will use the standard GIA scale for diamond color:
| EXCELLENT | VERY GOOD | GOOD | FAIR | POOR | |
|---|---|---|---|---|---|
| < .50 CT | D – G | H – I | J – K | L – M | > M |
| .51 – 1.0 CT | D – F | G | H – I | J – K | > K |
| 1.0 – 2.0 CT | D – F | G – H | I – J | > J | |
| > 2.0 CT | D – F | G | H – I | > I | |
| FLUORO | NONE | FAINT – MEDIUM | STRONG | VERY STRONG |
8 carat radiant cut clarity
| EXCELLENT | VERY GOOD | GOOD | FAIR | POOR | |
|---|---|---|---|---|---|
| < .50 CT | FL – VS2 | SI1 – SI2 | I1 | I2 | > I2 |
| .51 – 1.0 CT | FL – VS1 | VS2 – SI1 | SI2 | I1 – I2 | > I2 |
| 1.0 – 2.0 CT | FL – VVS2 | VS1 – VS2 | SI1 – SI2 | I1 | > I1 |
| > 2.0 CT | FL – VVS2 | VS1 – VS2 | SI1 | SI2 | > SI2 |
ASET and Idealscope
Both ASET and Idealscope images can help you to better exaluate the light performance of your diamond. Both tools will reveal areas of light leakage in white, but an ASET reading contains more detailed information. Because of this, it is the preferred method for evaluating fancy cut diamonds. However, because of the idealscope’s simplicity, it is a more user-friendly tool for non-gemologists. All you need to know when reading an idealscope is that white areas represent light leakage (bad) and red areas indicate light return (good).
Check out these images below for examples of ASET and Idealscope readings for radiant diamonds:
