Cushion vs Radiant Cut: Soft Corners or Sharp Ones

These two get confused because the outlines overlap. A squarish radiant and an elongated cushion, seen small on a phone, are genuinely hard to separate. And unlike the emerald and radiant comparison, where the faceting is opposite, here both stones are brilliant-cut. The optics are similar. The geometry is not.

It really is about the corners

A cushion's corners are rounded — a continuous curve from side to side, no vertex. A radiant's are cropped: the corner is cut off at an angle, leaving a short straight edge and two distinct vertices.

From that one difference, everything else follows.

• Durability. A rounded corner has no thin point to chip, which makes the cushion one of the safest shapes there is. A radiant's cropped corners are already the protective solution to a square's sharp points, so it is safe too — but it wants prongs seated on those corners, and a cushion does not care where its prongs go.
• Wedding bands. A radiant's straight parallel sides meet a straight band cleanly. A cushion's gentle curve means slightly more chance of daylight underneath. Neither is difficult by fancy-shape standards.
• Halos. A cushion halo traces a soft square and is the classic look. A radiant halo is more angular and more graphic. Both work; they are different rings.
• Period. Rounded corners read Victorian and antique. Cropped corners read 1970s onward. If the ring is going next to vintage-styled jewellery, this is the deciding factor.

Side by side

	Cushion	Radiant
Corners	Rounded, continuous curve	Cropped, angular
Sides	Gently convex, pillowed	Straight and parallel
Reads as	Antique, soft, romantic	Modern, sharp, architectural
Faceting styles available	Crushed ice or chunky	Crushed ice or chunky
Corner prongs needed	No — prong placement is free	Yes, on the cropped corners
Straight wedding band	Often	More often
Face-up size per carat	Small — usually cut deep	Small — also cut deep
Cut grade from a lab	None	None

The row people skip

Look again at the faceting row. Both shapes come in both styles, and that is more important than choosing between the shapes at all.

A crushed ice cushion and a crushed ice radiant behave almost identically: both glitter finely, both hide inclusions and colour well, both let you buy an SI1 and an I comfortably. A chunky cushion and a chunky radiant also resemble each other more than either resembles its crushed ice counterpart.

In other words, the faceting decision cuts across the shape decision and matters more. If you have not read crushed ice or chunky, that is the question to settle before this one.

Which to choose

Choose the cushion if you want an antique or vintage feel, if the ring will sit alongside milgrain and softer detailing, if you want the halo look that shape is best known for, or if you like a softer outline on the hand.

Choose the radiant if you want something sharper and more contemporary, if a plain straight wedding band is important, if you like a stronger geometric outline, or if you are drawn to the emerald cut's shape but want brilliant-cut sparkle. More on it in what is a radiant cut diamond and radiant cut engagement rings.

What to specify

1. Faceting style first — crushed ice or chunky — before choosing between the shapes.
2. A close crop of the corners for each stone you are comparing.
3. Millimetres and depth percentage for both, since both shapes are cut deep.
4. Ratio, calculated from those figures.
5. For a radiant: prongs seated on the cropped corners.
6. Rotating video in ordinary indoor light for both.
7. The same ring quoted in both shapes, so the choice is not abstract.

Frequently asked questions