Elongated Cushion Cut Diamond Guide: Ratio, Faceting, Size and Settings

What is an elongated cushion cut diamond?

A cushion cut diamond has a square or rectangular outline with gently rounded corners and softly curved sides, a bit like a pillow, which is where the name comes from. An elongated cushion cut diamond is simply the rectangular version: noticeably longer than it is wide. It is a brilliant-style cut, meaning it uses many triangular and kite-shaped facets to scatter light, rather than the long parallel steps of an emerald cut. Our complete cushion cut buying guide covers the square version in full.

The shape has old roots. Before modern cutting tools, diamonds were often polished into softly squared outlines with high crowns and small tables, the style now called the old mine cut. The modern cushion keeps that rounded-rectangle outline but adds a more precise facet pattern; our page on how the modern cushion grew out of the old mine cut shows the differences. Elongated cushions sit between two families: they appear in our guide to square and cushion cuts, from princess to Flanders and in the wider family of elongated diamond cuts.

On a GIA report the shape is listed as a cushion brilliant or a cushion modified brilliant, with measurements given as length × width × depth in millimetres. Diamond is 10 on the Mohs hardness scale, with a refractive index of about 2.42, and that is the same whether the stone is natural or lab-grown. Hardness is not toughness, though: a diamond can still chip if a thin edge takes a hard knock. The cushion's rounded corners have no sharp points, which makes it a practical shape for everyday wear.

To see where the cushion fits among all the shapes, start with our introduction to every diamond shape. If a term on this page is new to you, the plain-English jewellery glossary explains it.

What ratio makes a cushion cut diamond elongated?

The length-to-width ratio compares how long the stone is with how wide it is. Take the first two measurements on the grading report and divide the larger by the smaller. A cushion measuring 7.00 × 5.60 mm has a ratio of 1.25. A perfectly square cushion sits at 1.00.

There is no official cut-off between square and elongated. In practice the trade treats about 1.15 and above as elongated, and 1.20–1.35 is the band most people end up choosing: long enough to make the finger look slimmer, still clearly a cushion rather than an oval or a rectangle. If you are torn between the two outlines, our square vs elongated cushion comparison lays them side by side.

GIA does not give cushions an overall cut grade, so you judge the cut from the proportions, the polish and symmetry grades and, above all, how the stone looks in a video. As a rough guide, many attractive cushions sit at a total depth of about 61–68% and a table (the large flat top facet) of about 58–68% of the width. Cushions are often cut deep to save weight from the rough crystal, and a stone much deeper than about 70% can look small and dark for its carat weight.

Elongated cushions can also show a bow-tie: a dark band across the middle where light leaks out instead of returning to your eye. It is usually milder than in an oval or pear, but check it. A faint bow-tie that shifts as the stone moves is normal and adds contrast; a black band that stays put in every position points to poor proportions.

Cushion brilliant or crushed ice: which faceting style suits you?

Two cushions with the same ratio and grades can look completely different, because there are two main faceting styles underneath the table. This is the single biggest choice after the ratio, and photos often fail to show it.

• Cushion brilliant (often called chunky or antique style): larger pavilion facets (the pavilion is the lower, pointed half of the stone) that throw bold, distinct flashes of white light and colour. The facet pattern is crisp and easy to read, and many people feel it looks closest to an old mine cut.
• Crushed ice (a type of cushion modified brilliant): an extra row of facets on the pavilion breaks light into many small pinpoints, giving a glittery look like crushed ice in a glass. It hides small inclusions well and can look very bright, but some people find it busy or less defined, especially in larger sizes.
• Hybrids: many modern cushions fall between the two, with a mostly chunky pattern and a little extra faceting. Judging by eye matters more than the label.

The grading report does not settle the question. 'Cushion modified brilliant' on a GIA report usually means extra pavilion facets, but not every modified cushion looks like crushed ice, and the term covers several patterns. Watch a 360° video in steady light and look at the size of the flashes: large, blocky flashes mean a chunkier cut; fine, scattered glitter means crushed ice. Our guide to crushed ice and cushion modified faceting shows real examples of each.

How big does an elongated cushion cut diamond look?

Cushions tend to be cut deeper than most shapes, so they usually face up (look from above) smaller per carat than an oval or a round. The elongated version helps a little, because its length catches the eye, but the millimetre measurements matter more than the carat weight. The table below gives typical sizes for a cushion at about 1.25 ratio and average depth.

Treat these as a starting point only. Two 1.00 ct elongated cushions can differ by 0.5 mm or more in length, depending on how deep they are cut. When comparing stones, multiply length by width to get a rough face-up area: a 1.00 ct stone at 6.6 × 5.3 mm (about 35 mm²) will look noticeably larger than one at 6.2 × 5.0 mm (31 mm²), even though the weight is the same.

Smaller elongated cushions, from about 0.20 to 0.50 carat, work well as earrings, in pendants and as side stones. For a centre stone in an engagement ring, most people find the shape reads clearly from about 0.70 carat upwards, though that is a matter of taste rather than a rule.

What colour and clarity should you choose for an elongated cushion?

Cushions are known for holding colour. Their depth and rounded corners tend to concentrate any warmth, and in an elongated cushion that tint often shows at the two short ends. In white gold or platinum, most people are happy from H colour or better; if you are sensitive to a warm tint, look at G or higher. In yellow or rose gold, I or J can look white, because the metal warms everything around it.

For clarity, aim for an eye-clean stone: no inclusions (internal features) you can see without magnification at normal viewing distance. Crushed ice faceting is very forgiving, and a well-chosen SI1 or even SI2 can be eye-clean. A chunky cushion brilliant has larger, calmer facets, so inclusions are easier to spot; VS2 is a safer target there, especially above 1.5 carat. Check the plotting diagram on the report, which maps where each inclusion sits.

• White metal: G–H colour; VS2 in chunky cuts, VS2–SI1 in crushed ice.
• Yellow or rose gold: I–J colour can look white; same clarity targets.
• Watch for: dark crystals under the table and feathers (small internal cracks) that reach the surface near a corner.

That same colour-holding habit is why the cushion is one of the most popular shapes for fancy coloured diamonds, such as yellow and pink. A cutter can use the depth to deepen the colour seen face-up. Natural fancy colours are rare and priced by intensity; lab-grown coloured diamonds are widely available, and their colour is often created or enhanced after growth, which the report will state.

How does an elongated cushion compare with oval, radiant and emerald cuts?

The oval is the shape most often weighed up against an elongated cushion: both are soft and slimming, but the oval looks bigger for its weight while the cushion has a more vintage, pillowy outline. Our oval vs elongated cushion guide, point by point goes deeper. If you like straighter sides, the elongated radiant cut keeps the brilliant sparkle with cropped corners, and our page on radiant vs cushion differences in sparkle and outline explains the trade-offs.

For a calmer, mirror-like look, the step-cut elongated emerald is the opposite of a crushed ice cushion. You can also see how a cushion stacks up against a round brilliant and our Asscher vs cushion comparison for square shapes.

What is the best setting for an elongated cushion cut diamond ring?

Because a cushion has no sharp points, setting choices are mostly about look and comfort rather than protection. The common options for an elongated cushion engagement ring:

• Four claws: one at each corner, the classic choice. Rounded or slightly flattened claws follow the soft corners; double claws add security and a vintage feel.
• East-west: the stone is turned sideways across the finger, a modern look that sits lower and catches less.
• Bezel or half-bezel: a thin rim of metal around the edge; very secure for active hands, though it hides a little of the outline.
• Halo: a ring of small diamonds that follows the cushion outline and adds face-up size, useful because cushions are cut deep.
• Hidden halo: small diamonds around the girdle (the outer edge), seen from the side rather than from above.
• Three-stone: trapezoid, pear or smaller cushion side stones suit the soft rectangle.

Elongated stones need claws placed so the stone sits straight and does not twist, and the gallery (the metal under the stone) should be low enough to let a wedding band sit flush. See setting ideas that suit elongated shapes and our cushion setting styles, from halo to hidden halo for examples.

How much does an elongated cushion cut diamond cost in Australia?

Elongated cushions are cut from both natural and laboratory-grown diamond, and the two look identical to the eye. Lab-grown diamonds are real diamond, grown in a laboratory by CVD or HPHT methods rather than mined; they cost much less and are easy to find in larger sizes. Natural diamonds are rarer and formed deep underground, mostly between one and three billion years ago. Both should come with an independent grading report from a lab such as GIA or IGI, which states clearly whether the stone is natural or lab-grown.

These are broad ranges only; prices move with the market and with the exact grades. Cushions usually cost less per carat than rounds of the same weight, colour and clarity, partly because more of the rough crystal can be kept. Within cushions, a well-proportioned elongated stone at 1.20–1.35 is often priced a little above an average square cushion, simply because good ones are in demand. What moves the price most is carat, colour, clarity and how well the stone is cut.

How do you choose an elongated cushion cut diamond? Step by step

1. Read the report. Confirm the shape, measurements, colour, clarity, polish and symmetry, and whether the diamond is natural or lab-grown.
2. Work out the ratio. Divide length by width; aim for about 1.20–1.35 if you want a clearly elongated look.
3. Check depth and table. Around 61–68% depth is typical; a stone far deeper than 70% will look small for its weight.
4. Pick a faceting style. Watch a 360° video to see whether the stone is chunky, crushed ice or a hybrid, and decide which you prefer.
5. Look for a bow-tie. A faint shifting band is fine; a dark band that never moves is not.
6. Compare face-up size. Multiply length by width in millimetres rather than relying on carat weight.
7. Plan the setting. Choose claws, bezel or halo and check a wedding band can sit flush before you commit.