Radiant Cut Diamond Guide: Quality, Clarity, Color And Cost


A diamond’s length to width ratio signifies how proportionate the diamond is with its intended shape (i.e. square vs. rectangular) and is determined by dividing the diamond’s length by width. As an example, if a diamond’s length measures 5mm and its width is 3.5mm, the length to width ratio is 1.43.

The ratio you choose for your radiant diamond is entirely dependent on what you find to be the most aesthetically pleasing. A common range for radiant length to width ratios is 1.00-1.35, with the lower end indicating a more square shape. Length to width ratios can go up to 2.0 for a more rectangular shape.


  • Clarity describes how clean a diamond is. In other words, it measures of how free of inclusions and blemishes it is.The GIA ranks Clarity on the following scale:
    • IF – Internally Flawless
    • VVS1 – Very Very Small Inclusions
    • VVS2 – Very Very Small Inclusions
    • VS1 – Very Small Inclusions
    • VS2 – Very Small Inclusions
    • SI1 – Small Inclusions
    • SI2 – Small Inclusions
    • I1 – Inclusions
    • I2 – Inclusions


As we mentioned above in the pros and cons of the radiant cut, radiant cut diamonds tend to look bigger than most of the other diamond shapes of the same carat weight.

This isn’t an accident. When Henry Grossbard designed the radiant cut in the 1970s, he did so aiming to create a diamond cut that looked as large as possible. His aim was to maximize the natural beauty of each diamond, rather than to cut it to maximize weight, as was the typical approach at the time.

Because of the radiant cut’s broad, shallow design, more of the diamond is visible when it’s set in a ring, helping to create the appearance of a larger stone. The end result is a shape that combines the best of the brilliant cut — namely, its brilliance — with a larger perceived size.


Emerald cuts fit well in many different styles, but they really fit perfectly with more understated settings. Emerald cuts go well with solitaire and simple pave settings, and are perfect for three stone settings.


Although the radiant cut isn’t quite as brilliant as the round brilliant cut, it’s not very far behind. Because of the 70 facets in its pavilion and crown, the radiant cut offers impressive brilliance and fire. This makes the radiant cut a great choice if you want a non-round diamond with a beautiful sparkle.

Larger perceived size than other diamond shapes

The radiant cut is well known for looking larger than most of the other diamonds of the same carat weight, giving it some extra presence on your fiancé-to-be’s finger.

Better durability than other square diamonds

The radiant cut is often compared to square diamonds, such as the princess cut. Although it looks quite different (the princess cut is square, while the radiant cut is square or elongated), it’s easy to see the similarities.

Excellent value for money

The cutting process for the radiant diamond uses a large percentage of the original rough diamond, with very little going to waste. This means that a loose radiant diamond will be priced lower on a per-carat basis than most other diamond cuts. In fact, the radiant cut diamond is one of the most affordable diamond shapes.


In addition to Cut and Clarity, you’ll want to review Radiant Cuts for their Color. As graded by the GIA, Color rankings range from D to Z. The D grade represents the most clear, colorless diamonds while the Z grade represents those with noticeable yellow or brown tint.

The differences in Color for Radiant Cuts are slightly easier to perceive than other diamond shapes. Still, we generally recommend an H Color or better for Radiant Cut Diamonds, allowing your budget to be spent on other aspects, like Cut quality. To the naked eye, an H grade will appear white and colorless to the naked eye.