Cushion Cut Diamonds: buyer checklist
The cushion is a squared outline with rounded corners and softly curved sides, descended from the antique old mine cut that predates modern brilliant faceting. It has more character and warmth than the sharper contemporary shapes, and it is consistently good value per carat.
There is one thing about cushions that catches out more buyers than anything else, and it is not on any report: two completely different facet arrangements are both sold simply as “cushion cut”. They look nothing alike. Choosing the wrong one is the most common disappointment in this shape, and it is entirely avoidable.
This page is about choosing the stone. For settings and finished rings, see cushion cut diamond rings.
- Decide facet style first — classic or crushed ice. This is the whole character of the stone.
- Decide square or rectangular, and the ratio.
- Compare millimetre spread, because cushions are often cut deep.
- Set clarity expectations according to the facet style.
- Consider metal alongside colour grade.
The main options to compare
Classic versus crushed ice
A classic or standard cushion has fewer, larger facets. It produces broad, distinct flashes of light — you can see individual sparkles, and the effect is chunky and characterful, closer to an antique stone. It is the more traditional look.
A modified cushion, usually called crushed ice, has many more small facets beneath the table. Instead of distinct flashes it produces a fine, scattered glitter, like light on broken ice. It is busier and more sparkly, and it is currently the more commonly produced of the two.
Both are legitimate and both are simply labelled cushion cut. The report will not usually distinguish them — you have to look at the stone or ask directly. If you have a mental image of a cushion from a photograph, work out which of the two it was, because being handed the other is the classic disappointment here.
Square or rectangular
Cushions are cut with length-to-width ratios from about 1.00, which reads as a soft square, up to around 1.30 or beyond, which reads as a distinct rectangle. Both are common. A squarer cushion looks fuller and more antique; a rectangular one elongates the finger. Specify which you want.
Origin
Natural or laboratory-grown, the largest single price influence. Both are diamond and both are graded identically; origin must be stated on the report. See lab-grown vs natural diamond.
Quality and practical factors: facet style, length-to-width ratio, spread and setting choice
How facet style changes what else you need
This is the practical consequence most buyers never hear. The facet style determines how forgiving the stone is on clarity.
A crushed-ice cushion hides inclusions extremely well. The scattered, busy light pattern breaks up the view into the stone and disguises almost anything. You can buy well down the clarity scale and see nothing.
A classic cushion is less forgiving. Its larger, more open facets give a clearer view into the stone, so inclusions show more readily and you should expect to need a somewhat higher clarity grade. Not as demanding as an emerald cut, but not as relaxed as a crushed ice.
So the facet style is not only an aesthetic decision — it changes your budget allocation. Decide it first.
Spread, and the depth problem
Cushions are frequently cut deep to retain weight from the rough, and the variation in this shape is wider than in most. Two cushions of identical carat weight can differ noticeably in face-up size, which means carat weight is a poor guide to how big the stone will look.
Always ask for millimetre measurements and compare candidates on those. Check the depth percentage on the report — an unusually high figure means weight is sitting below the girdle where nobody will ever see it. This single check is worth real money in this shape.
Colour, and the traditional pairing
Cushions show a little more body colour than round brilliants. There is a reason cushions and yellow gold have a long history together: the warm metal works with a warmer stone rather than against it, so a lower colour grade reads as white. If you are setting in white metal, allow a grade; if in yellow or rose gold, take the saving deliberately. See diamond colour guide.
Setting choice follows facet style
A crushed-ice cushion pairs naturally with a halo, since both scatter light and the effect is coherent. A classic cushion is usually better left unadorned, so its larger flashes read clearly rather than competing with surrounding sparkle. The rounded corners make cushions durable and easy to set — there are no vulnerable points or sharp corners.
Price and budget considerations
- Cushions cost less per carat than round brilliants, because the shape uses the rough efficiently. Good value before any other decision.
- Diamond origin — the largest lever available.
- Carat thresholds — buying just under a round weight remains the most reliable saving.
- Spread is where cushions are won or lost. Comparing millimetres rather than carats is worth more in this shape than in almost any other, given how much depth varies.
- Clarity — a substantial saving in a crushed-ice cushion, a more modest one in a classic.
- Colour with warm metal — the traditional pairing, and a genuine saving with no visible cost.
See diamond price South Africa. Quotes are dated and specification-based.
Certification, documentation and trust checks
Cushions are graded on the four characteristics in GIA’s grading methodology, with report types described in GIA’s guide to report types.
- No overall cut grade is issued for cushions. Read polish, symmetry and the proportion figures, and pay particular attention to depth percentage.
- The report will not usually tell you the facet style. Ask directly, or look at the stone. This is the most important characteristic of a cushion and it is not documented.
- Verify the report number on the issuing laboratory’s own database, and check the measurements match.
- Read the origin and treatment lines.
- Study the clarity plot — and interpret it in light of the facet style, since the same grade means different things in a classic versus a crushed-ice stone.
- See diamond certificate explained for reading a report line by line.
The antique connection
The cushion descends from the old mine cut, which was the dominant diamond shape for much of the eighteenth and nineteenth centuries, before electric light and modern cutting equipment changed what cutters optimised for. Old mine cuts were shaped by candlelight and lamplight: larger facets, a high crown, a small table and a chunky pattern of flashes that read beautifully in low, warm light.
That lineage is why the classic cushion has the character it does, and why it suits vintage-style settings so naturally. It also explains something buyers sometimes find surprising: a classic cushion can look less brilliant than a modern round under bright showroom lighting, and then come alive in candlelight or evening light in a way the round does not. If the ring will mostly be seen in ordinary daily light, judge it in ordinary daily light.
Genuine antique old mine cuts are a separate market from modern cushions, with their own considerations around chips, wear and the absence of modern grading. If that interests you, say so — it is a different conversation from choosing a contemporary cushion.
Common mistakes to avoid
- Not knowing the facet style exists. By far the most common cushion mistake — buyers picture one and are handed the other, and only realise once the ring is made.
- Comparing on carat weight. With depth varying as much as it does in cushions, weight tells you remarkably little about size.
- Paying for high clarity in a crushed-ice stone. The faceting already hides inclusions; you are buying certificate lines.
- Assuming all cushions are square. Many are noticeably rectangular. Specify the ratio.
- Ignoring depth percentage and ending up with a small-looking stone at full price.
- Putting a classic cushion in a busy halo, which drowns the very flashes that make it distinctive.
Matching the facet style to the setting
Once you have chosen a facet style, it should inform the setting rather than being decided separately. The two work together, and pairing them badly wastes what you paid for in the stone.
A crushed-ice cushion already produces a busy, scattered shimmer. Surrounding it with a halo of small brilliant accents extends that effect outward and the whole ring reads as one continuous field of light. It is a coherent pairing and a popular one.
A classic cushion is the opposite case. Its appeal is the distinct, larger flashes you can pick out individually, and surrounding it with a halo of tiny stones drowns exactly that quality — the accent sparkle competes with the centre stone rather than supporting it. Classic cushions are almost always better in a solitaire, a three-stone or a vintage-style setting with metalwork rather than accent stones around the centre.
If you have fallen for a classic cushion and also want a halo, consider a hidden halo beneath the stone instead, which adds detail from the side without interfering with the face-up view.
Next step: narrow the shortlist and enquire
Settle the facet style first, then the ratio, then origin and budget. Ask to see one of each facet style side by side — five seconds of looking settles a decision that reading cannot. Then compare candidates on millimetre spread rather than carat weight, and set your clarity expectation according to which style you chose.
Move to settings at cushion cut diamond rings, or compare outlines at diamond shapes. For the whole process, the diamond buying guide.
Continue to the relevant buying guide or book expert guidance
Tell us the size and budget you have in mind, and we will show you a classic cushion and a crushed-ice cushion together. Most people know immediately which one they want once they see both — and knowing that before you choose a stone changes everything else about the specification.
Compare cushion cut diamonds in person