Asscher vs Radiant: Comparing Asscher and Square Radiant Diamonds

Asscher vs radiant: what is the difference?

Both shapes start as a square with the corners trimmed off, so from across a room they share an outline. Up close they belong to two different faceting families. The Asscher is a step cut: long, flat facets arranged in parallel rows, like steps down a staircase, around a high crown and a fairly small table (the large flat facet on top). The square radiant is a mixed cut, also called a modified brilliant. It keeps the cut-cornered outline but covers the crown and pavilion (the top and bottom halves of the stone) with the triangular and kite-shaped facets of a round brilliant.

Joseph Asscher of the I.J. Asscher company in Amsterdam designed the original Asscher in 1902. The version most jewellers sell today has about 58 facets, while the trademarked Royal Asscher, released in 2001, has 74. Henry Grossbard introduced the radiant in the late 1970s as the first cut to give a cut-cornered stone full brilliant faceting, and most radiants have about 70 facets. Our guides to the Asscher cut, from its 1902 origins to today and radiant cut diamonds in every ratio cover each shape on its own.

The grading report tells you which one you are looking at. On a GIA report an Asscher is usually described as a Square Emerald Cut, and a square radiant as a Cut-Cornered Square Modified Brilliant. That wording matters when you search online, because the same stone can be listed under different shape names by different sellers. If you want a square step cut with sharp, untrimmed corners instead, that is the carré, the original square step cut. Any unfamiliar term here is explained in our plain-English jewellery glossary.

How do Asscher and square radiant diamonds look on the hand?

On the hand an Asscher reads as an octagon. Its corners are cut much larger than a radiant's, so the outline looks almost eight-sided. Looking down into the stone you see a series of concentric squares, often called the hall of mirrors, crossed by an X of reflections running from corner to corner, known as the windmill. The effect is calm, geometric and strongly Art Deco. Our page on how the Asscher windmill pattern forms explains what makes that X crisp in one stone and muddy in another.

A square radiant reads as a bright square with clipped corners. Because the corners are smaller, it looks more like a square than an octagon, and its face-up pattern is busy and fragmented, the look people call crushed ice. It stays lively even in dim indoor light. In style it sits between a princess and a cushion; our overview of how princess, radiant, cushion and Flanders cuts differ shows the whole square family together.

• Asscher: vintage, architectural, quiet. Suits people who like clean lines, step-cut emeralds or 1920s jewellery.
• Square radiant: bright, modern, a little less formal. Suits people who want maximum sparkle in a square outline.
• Both: sit squarely on the finger and look the same width in every direction, so neither makes the finger look longer the way an oval does.

For either shape to read as a true square, the length-to-width ratio (length divided by width, from the report) should be about 1.00–1.05. Above roughly 1.05 a radiant starts to look slightly rectangular, which some people like and others do not; radiant ratios from square to elongated shows how the look changes step by step. An Asscher much above 1.05 begins to look like a short emerald cut.

Asscher vs radiant: which looks bigger per carat?

Face-up size is how wide a diamond looks from above, and it depends on how much of the weight sits in the outline versus hidden in the depth. Both the Asscher and the square radiant are fairly deep cuts with high crowns, so both face up smaller than a round brilliant of the same weight. A 1 carat round is usually about 6.4 mm across; a 1 carat Asscher or square radiant is usually about 5.5 mm.

Between the two shapes, the difference at the same weight is only around a tenth of a millimetre, and that is smaller than the spread between a well-proportioned stone and a deep one of the same shape. The number that really decides face-up size is the total depth (height as a percentage of width). Many well-cut Asschers sit around 60–68% depth, and many square radiants around 61–67%. A stone deeper than about 70% carries extra weight underneath and can look a size smaller than its carat weight suggests.

Two optical effects also play a part. The Asscher's larger corners remove a little outline area, so at the same width it covers slightly less of the finger. The radiant's brighter, busier sparkle tends to make its edges look fuller. In practice most people who see a 1 carat of each side by side describe them as the same size, and choose on the sparkle instead.

Which sparkles more, an Asscher or a radiant?

Diamond has a refractive index of about 2.42, so both cuts bend light strongly; the difference is in how the facets return it. The radiant's many small brilliant facets break light into lots of quick, small flashes: high scintillation (the twinkle you see as the stone or your hand moves). The Asscher's long step facets return fewer, larger flashes and broad planes of bright and dark, giving strong contrast and a slower, mirror-like sparkle.

Neither is more sparkly in an absolute sense; they sparkle differently. An Asscher looks its finest in directional light, such as daylight or spotlights, where the steps flash on and off. A radiant is lively under almost any light, including the soft, diffused light of an office. If you are also weighing a princess, see princess vs radiant sparkle, compared and how an Asscher differs from a princess.

What colour and clarity do you need for an Asscher or a radiant?

This is where the two cuts differ most in what you spend. A step cut has large, open facets, a bit like looking through a window, so inclusions (internal features such as crystals or feathers) are easier to see. Most Asschers need VS2 or better to be eye-clean, meaning no inclusions visible without magnification at normal viewing distance, and VS1 is a safer start above about 1.5 carats. Where the inclusion sits matters as much as the grade; our guide to Asscher clarity grades that stay eye-clean shows which positions hide and which do not.

The radiant's brilliant faceting breaks up the view, so a carefully chosen SI1, and sometimes an SI2, can look clean to the eye. For colour, step cuts show body colour fairly openly, while radiants tend to collect a little warmth in the corners. In white gold or platinum, most people are happy from G–H in an Asscher and H–I in a radiant; in yellow or rose gold, I–J can look white in either cut.

• Asscher, white metal: G–H colour, VS2–VS1 clarity.
• Square radiant, white metal: H–I colour, SI1 eye-clean or better.
• Either, yellow or rose gold: I–J colour can look white once set.
• Check: the plotting diagram on the report, especially for inclusions under the Asscher's table.

Are Asscher and radiant diamonds durable, and how should they be set?

Diamond is 10 on the Mohs hardness scale, but hardness is not toughness: a thin edge or sharp corner can chip if it takes a knock. The good news is that both shapes have cut corners, which remove the fragile points that make a princess cut vulnerable. Neither has a sharp tip, so both are well suited to everyday wear.

• Four claws: the usual setting for both, with one claw on each cut corner. Flat or tab-style claws hug the Asscher's wide corners neatly.
• Double claws: eight claws, two per corner, add security and frame the outline.
• Bezel: a thin rim of metal around the edge suits the Asscher's Art Deco lines and protects the girdle (the outer edge).
• Halo: small diamonds around the centre stone make either shape look larger; a square halo suits the radiant, an octagonal one the Asscher.

Because the Asscher has a high crown, it sits a little taller than a radiant of the same face-up size, so a slightly lower basket keeps it from catching. Our page on setting styles that suit an Asscher shows examples. Both shapes have straight sides, so a straight wedding band usually sits flush beside an Asscher cut engagement ring or a radiant without needing a curve.

How do Asscher and square radiant diamonds compare side by side?

If you like the Asscher's step-cut look but want a longer outline, compare it with its rectangular cousin in our emerald vs Asscher comparison. If the softer, pillow-like corners of a cushion appeal more than either, see square and elongated cushion shapes. For every shape on one page, start with our guide to every diamond shape.

How much does an Asscher vs radiant diamond cost in Australia?

Both shapes usually cost less per carat than a round brilliant of the same weight, colour and clarity, because cutters keep more of the rough crystal and demand is lower. Between the two, the price per carat at the same grades is broadly similar. What changes the final figure is that Asscher buyers usually need a higher clarity grade to stay eye-clean, while a radiant can often drop to SI1.

These are broad ranges only; prices move with the market, the exact grades and how well the stone is cut. Lab-grown diamonds are real diamond, grown in a laboratory rather than mined, with the same hardness and refractive index. They cost much less than natural diamonds and are easy to find in larger sizes, while natural Asschers and radiants are rarer. Whichever you choose, ask for an independent grading report from a lab such as GIA or IGI, which will state whether the stone is natural or laboratory-grown.

Which should you choose, an Asscher or a square radiant?

• Choose an Asscher if you love Art Deco or vintage jewellery, prefer a calm, mirror-like look to constant twinkle, and are happy to put more of your budget into clarity.
• Choose a square radiant if you want the most sparkle a square can give, often wear your ring in soft indoor light, or want your budget to go further on carat by choosing an eye-clean SI1.
• Either works if durability is your main concern: both have protected corners and suit active hands with a sound setting.

If you are leaning towards the radiant, our dedicated page on the square radiant diamond, its proportions and settings goes deeper on depth, table and corner brightness. If you are torn between an Asscher and something softer, the Asscher vs cushion comparison is the natural next read.

How do you choose between an Asscher and a square radiant? Step by step

1. Read the shape on the report. Square Emerald Cut (or Asscher) means step cut; Cut-Cornered Square Modified Brilliant means radiant. Confirm whether the stone is natural or lab-grown.
2. Check the ratio. Divide length by width; aim for 1.00–1.05 for a true square.
3. Check depth and face-up size. Compare the millimetre measurements, not just carats, and be wary of depths above about 70%.
4. Match clarity to the cut. VS2 or better for an Asscher; SI1 can work for a radiant if the inclusions are off-centre.
5. Watch both in the same video light. Look for a crisp windmill in the Asscher and bright corners in the radiant.
6. Plan the setting. Four or eight claws, a bezel or a halo, set low enough that the crown does not catch.