Square vs Elongated Cushion Diamond: Which Cushion Shape Suits You?

What is the difference between a square and an elongated cushion diamond?

A cushion cut is a diamond with a squarish or rectangular outline, softly rounded corners and gently curved sides, a bit like a pillow seen from above. It descends from the old mine cut of the 1700s and 1800s, and modern cushions keep that soft outline while using brilliant-style faceting (triangular and kite-shaped facets) for sparkle. It is one of the shapes in our full list of 34 diamond cuts.

The only thing separating a square cushion from an elongated one is the length-to-width ratio: the stone's length divided by its width, both taken from the grading report. A square cushion is close to 1.00, so it looks almost equal on every side. An elongated cushion is noticeably longer than it is wide, usually somewhere between 1.15 and 1.35, so it reads as a soft rectangle. Everything else, from the facet pattern to the rounded corners, can be identical.

Cushions belong to the square and cushion family of cuts alongside the princess, radiant and Flanders, and the longer version has its own page: our full guide to elongated cushion cut diamonds. If a term below is new to you, our plain-English jewellery glossary explains it.

Diamond itself is 10 on the Mohs hardness scale with a refractive index of about 2.42. The cushion's rounded corners are a practical advantage here: unlike a princess cut, there are no sharp points to chip, which is one reason cushions are popular for everyday rings.

What is a good ratio for a cushion cut diamond?

There is no single correct ratio, only the outline you prefer. Grading labs such as GIA do not give cushions an overall cut grade, so the ratio, proportions and how the stone looks in a video carry most of the weight. As a working guide:

Ratio works the same way across every fancy shape, and our guide to how ratio changes every diamond shape shows the pattern. For cushions, the band from 1.05 to 1.10 is the awkward middle: it is not truly square, but not long enough to look deliberately elongated. If you want a square, aim for 1.05 or below; if you want a rectangle, go to 1.15 or above so the difference is obvious on the hand.

Proportions matter too. Many well-cut cushions sit at a total depth of about 61–70% and a table (the large flat top facet) of about 55–68% of the width. Cushions are often cut deeper than rounds, which keeps weight from the rough crystal but makes the stone face up smaller for its carat weight.

Square vs elongated cushion diamond: how do they compare side by side?

The square is the more traditional look and the one closest to the antique cushions people see in estate jewellery. It sits compactly, suits shorter or wider fingers well and keeps light return even across the stone. The elongated cushion is the newer favourite: it gives more length and finger coverage for the same weight and blurs the line between a cushion and an oval.

If you are torn between a long cushion and an oval, our elongated cushion versus oval comparison works through outline, sparkle and price point by point.

Square vs elongated cushion diamond: which looks bigger?

At the same carat weight, an elongated cushion usually looks a little bigger than a square one. Weight is spread along the length, so you see more surface from above, and the eye reads length as size. A square cushion keeps its weight more compact and often deeper. These are typical face-up sizes for well-proportioned stones:

These are ranges, not rules. Two 1 ct cushions can differ by half a millimetre or more face-up, because cushion depths vary so widely. Always compare the millimetre measurements on the report rather than the carat weight alone. A deep square cushion at 68–70% depth can look like a much lighter stone, while a well-spread one at about 62–65% faces up closer to its weight. Our comparison of which shapes face up largest for their carat weight puts cushions alongside the other cuts.

Our ratios and proportions for long cushions page goes further into how depth and ratio interact, and why a long cushion with a very high depth can still look small.

What is a crushed ice cushion, and does it matter for square or elongated?

Cushions come in two broad faceting styles, and GIA reports name them differently:

• Cushion brilliant: larger, well-defined facets, with pavilion main facets running from culet to girdle in a pattern descended from the old mine cut. It shows bold, chunky flashes of light, sometimes called a broad-flash look.
• Cushion modified brilliant: an extra row of facets on the pavilion (the lower half) breaks the light into many tiny sparkles. When the effect is strong it is called crushed ice, because the centre looks like broken ice rather than distinct facets.
• Hybrids: many modern stones sit between the two, with some definition and some crushed-ice sparkle.

Both styles appear in square and elongated cushions, but the effect changes with the ratio. In a square cushion, the pattern looks even and centred. In an elongated cushion, crushed ice can make the long middle look busy or slightly hazy, and it can also hide a bow-tie (the dark band across the centre of many elongated shapes). A broad-facet elongated cushion shows its pattern more clearly, which some people love and others find too geometric.

If you like the sparkle of crushed ice but want crisp cut corners, the crisper-cornered elongated radiant is the close relative to compare.

What colour and clarity should you choose for a square or elongated cushion?

Cushions tend to hold body colour more than rounds, because the deep pavilion and the faceting concentrate it. The ratio changes where that colour shows. In a square cushion it spreads fairly evenly. In an elongated cushion, warmth tends to gather at the two short ends, so a stone that looks white in the middle can show a faint yellow tint at the tips.

• Square cushion in white gold or platinum: H colour or better suits most people.
• Elongated cushion in white gold or platinum: G–H, as the ends show colour more readily.
• Either shape in yellow or rose gold: I–J can look just as white, because the metal warms the whole ring.
• Clarity: aim for eye-clean, meaning no inclusions (internal features) visible without magnification at normal viewing distance. In cushions that is usually VS2 or a carefully chosen SI1.

Crushed-ice faceting hides small inclusions well. Broad-facet cushions behave more like a step cut in the centre and can show an inclusion under the table more clearly, so check the plotting diagram on the report and look closely at the middle of the stone in the video.

What setting suits a square or elongated cushion engagement ring?

Because a cushion has no sharp points, claw placement is about looks and security rather than protecting a tip. The main options:

• Four claws at the corners: the classic choice for both shapes. On a square cushion they sit symmetrically; on an elongated cushion they emphasise the length.
• Double claws: eight claws in pairs, for extra security and a slightly softer, vintage look on a square cushion.
• Halo: a ring of small diamonds around the centre. On a square cushion it gives the familiar vintage look; on an elongated cushion it adds face-up size.
• Hidden halo: small diamonds around the girdle (the outer edge) under the stone, visible from the side. Popular with elongated cushions because it keeps the outline clean from above.
• East-west setting: an elongated cushion turned sideways across the finger for an unusual, modern look. A square cushion looks the same either way, so this only applies to long stones.

Elongated cushions sit longer on the hand, so check how a wedding band will sit beside the stone, especially with a hidden halo. Our definitions of claw, halo and girdle help when reading setting descriptions, and whether an oval or a long cushion suits your hand is worth a look if finger coverage is your main reason for going elongated.

How do cushions compare with radiant, princess, emerald and oval diamonds?

For a square stone with straighter lines, compare the cushion with square radiant diamonds, and then look at the Asscher vs square radiant guide if you also like the clean steps of a vintage Asscher. For the most architectural square, the carré, a true square step cut, is the opposite of a soft crushed-ice cushion.

On the elongated side, long emerald cuts trade sparkle for long mirror-like steps, while an oval diamond with no corners at all gives the smoothest outline. To see how these all fit together, our princess, radiant, cushion and Flanders comparison and the overview of all the main diamond shapes put them side by side.

How much does a cushion diamond cost in Australia, natural or lab-grown?

The ratio on its own has only a modest effect on price. A square and an elongated cushion with the same carat, colour, clarity and quality of cut usually sit in a similar range, although demand for elongated cushions can push well-cut long stones slightly higher. Cushions generally cost less per carat than rounds of the same grades, partly because the cut keeps more of the rough crystal; our page on how cushion prices compare with other shapes sets out the pattern.

Cushions are cut from both natural and laboratory-grown diamond. Lab-grown diamonds are real diamond with the same hardness and refractive index, grown in a laboratory rather than mined; they cost much less and are easy to find in larger sizes. Natural cushions are rarer. Both should come with an independent grading report from a lab such as GIA or IGI, and the report states which one you are looking at.

These are broad ranges only and move with the market and the exact grades. Within cushions, carat, colour and clarity move the price most, then the quality of the cut and how well the stone spreads for its weight. Paying for a deep cushion that faces up small is a common way people overspend.

How do you choose between a square and an elongated cushion? Step by step

1. Decide on the outline. Square for a classic, even look; elongated for length and finger coverage.
2. Work out the ratio. Divide length by width from the report. Aim for 1.00–1.05 for square or 1.15 and above for elongated, and avoid the 1.05–1.10 in-between zone unless you like it in person.
3. Check the millimetres. Compare face-up measurements, not just carat weight, and be wary of depths above about 70%.
4. Choose a faceting style. Broad facets or crushed ice: watch a 360° video of each, as photos rarely show the difference.
5. Look for a bow-tie. In elongated cushions, check the centre stays bright as the stone moves.
6. Match colour to metal. Go a grade whiter for an elongated cushion in white metal, as the ends show warmth.
7. Confirm natural or lab-grown. Read the report, then plan the setting and wedding band before you commit to the stone.