What to Look for When Buying a Radiant-Cut Diamond

A radiant-cut diamond is recognised by its rectangular or nearly square outline, clipped corners and brilliant-cut facets. Two radiant stones with the same carat weight can look noticeably different, because this shape may not have one ideal proportion or a cut grade applicable to every stone.

What Is a Radiant Cut?

Radiant is a rectangular or square diamond shape with clipped corners. It combines the outline of an emerald cut with the livelier light character of a brilliant cut. The clipped corners can make protection in a setting easier.

1. Choose the Length-to-Width Ratio

The ratio is found by dividing the stone's length by its width. Stones close to 1.00 appear square; as the ratio increases, the stone looks more elongated and rectangular. There is no single correct choice. Finger shape, setting and personal preference are the deciding factors.

• Nearly square: a more compact, symmetrical appearance.
• Moderate length: a balanced, modern and versatile look.
• Elongated radiant: a distinctive silhouette that makes the finger look longer.

2. Check the Crushed-Ice Appearance

In some radiant stones, the facets create many small flashes of light. This appearance is called crushed ice. Some people like this lively sparkle; others prefer larger, clearer flashes of light. A certificate alone does not show this preference: you need a video.

3. Examine Dark Areas and Light Distribution

View the stone from different angles. Broad dark areas that remain in the centre or corners can make the surface look less bright. A balanced radiant distributes light across its face as it moves, without one area remaining dark all the time.

4. Read Millimetre Dimensions Alongside Carat Weight

Carat is weight. In a stone that is too deep, weight can sit in the lower portion, making it look smaller from above than expected. Compare length, width and depth with stones of similar carat weight.

5. Check the Corners and Symmetry

The four clipped corners should look balanced. If one corner is noticeably narrower or wider, the stone may appear crooked in the setting. Assess the outline, opposite sides and centre line together.

6. Balance the Colour Grade with the Setting

In some radiant-cut stones, colour can be more visible at the corners. Buyers seeking a more colourless appearance in a white gold setting may place greater importance on colour grade. Yellow or rose gold can make a slightly warm tone part of the design.

7. Consider the Location of Clarity Characteristics

The faceted structure can hide some internal characteristics. Look beyond the grade to whether a characteristic is in the centre or near the edge and whether it is visible to the naked eye. An eye-clean VS stone can be a balanced option for many budgets.

8. Choosing a Setting

Prong settings that securely hold all four corners are common. A halo can make the visible surface look larger; a hidden halo adds sparkle from the side; a bezel provides a more protective frame. See the solitaire setting guide for a comparison.

Radiant-Cut Checklist

• Decide whether you want a square or elongated shape.
• Check the length-to-width ratio.
• Examine the crushed-ice appearance in an actual video.
• Check for persistent dark areas.
• Look at symmetry in the corners and outline.
• Compare millimetre dimensions alongside carat weight.
• Balance colour and clarity with the setting.
• Choose a setting that protects the corners.

See the diamond cut guide to compare other shapes and lab-grown diamond rings for current designs.

Frequently Asked Questions

Does a radiant cut look large on the finger?

An elongated shape and good distribution of face-up area can create a larger impression than some compact shapes with the same carat weight. Millimetre dimensions are decisive.

Are radiant and emerald cuts the same?

No. Their outlines may be similar, but radiant has livelier brilliant-style facets, whereas emerald has stepped, mirror-like facets.

Can a radiant cut have a bow-tie?

An elongated radiant stone may show a dark band in its centre. Its severity should be checked using an actual video and different lighting conditions.