Cut registry › Jewellery cuts › Square
Jewellery cuts · Step cut
The carré.
A plain square step cut with sharp uncut corners. On our census it is the best-performing non-round shape on the site, which is not where anyone expects to find it.
The short version
A square step cut diamond, known in the trade as a carré, is a square stone with sharp uncut corners and facets arranged in flat parallel steps rather than in triangles and kites.
It is the square counterpart of the emerald cut: the same step architecture, without the cut corners and without the elongation.
Definition
The carré is an Art Deco shape, most often seen as a side stone or in geometric bands from the 1920s and 1930s, and it has been revived steadily since. It is the strictest of the step cuts: four equal sides, four sharp corners, and nothing softened.
Because it keeps its corners, it is not an asscher. An asscher is a square step cut with the corners cut off. Take those cut corners away and the stone becomes a carré, gaining a harder outline and losing the protection those corners provide.
Like every step cut it is an open architecture. Long flat facets show what is inside the stone, so clarity and colour matter more here than they would in a brilliant of the same size.
Proportions
Commonly cited ranges against our measured reference stone. There is no standardised proportion set for a carré, so the left column is what the trade tends to use.
| Measure | Commonly cited | Our reference stone | What it does |
|---|---|---|---|
| Length-to-width | 1.00 to 1.05 | 1.00 | Square by definition. |
| Depth | 60% to 70% | 65.0% | The flat top, as a share of the width. |
| Table | 55% to 70% | 44.2% | Large, as on any step cut. |
| Pavilion angle | not commonly published | 40° | Close to the modern round brilliant’s, which is why it performs. |
| Facets | typically 50 to 60 | 69 | Counted as facets that actually reach the surface. |
GIA issues no cut-quality grade for a carré, and a report will usually describe it as a square step cut. As with the princess, the corners are the vulnerable part, and a setting that covers them is not optional.
Light
Measured on the census that runs on every cut on this site: 3,200 rays face-up, 2,200 at 20° tilt, on exact facet geometry, against T57 as the standard.
| Material | Useful light | Leak | Fire | Scintillation | Global | vs the standard |
|---|---|---|---|---|---|---|
| Diamond | 85.08% | 9.66% | 72.45 | 78.42 | 84.11 | −4.49 |
| Moissanite | 82.25% | 10.95% | 91.36 | 78.42 | 87.01 | −2.81 |
| Cubic zirconia | 84.65% | 11.15% | 82.65 | 78.42 | 86.19 | −5.58 |
| T57 standard, diamond | 92.28% | 1.88% | 78.85 | 71.82 | 88.61 | 0.00 |
This is the strongest non-round result on the site. The carré returns 85.08% of entering light usefully and leaks 9.66%, for 84.11 Global against the standard’s 88.61. Only the historic old european and the Portuguese, both round, score higher among the shapes we publish.
The reason is in the proportions table above. Its pavilion sits at 40°, within a degree or so of the angle Tolkowsky solved for, where most of the fancy shapes we measure sit well away from it. A step cut with the right pavilion angle returns light perfectly well. What the step architecture changes is the character of the return, not the amount.
It carries 69 active facets for 78.42 on scintillation, above the standard’s 71.82, and its fire reads 72.45. Broad flashes, not fine sparkle, and plenty of light behind them.
Where the light is: useful return across the face
Five equal bands across the stone. The carré returns 88.2% across the centre against 82.5% at the edges, a spread of 5.7 points, against the round-brilliant control’s 1.0. Far flatter than the princess, whose corners measurably darken.
Against the standard
Light return. 85.08% against the standard’s 92.28%, a Global gap of 4.49 points, which places it first of the twenty-one jewellery cuts we publish.
Sparkle character. 78.42 against 71.82. It throws more separate flashes than a round brilliant, but they are broad step-cut flashes rather than pinpoints.
Clarity. The carré needs more of it. Long open facets hide nothing, exactly as on an emerald cut.
Durability. Four sharp uncut corners, and the weakest point of the shape. V-prongs or a bezel are needed, as on a princess.
Price. Less per carat than a comparable round, and usually less than an asscher of the same size because the outline wastes less rough.
The baseline for all of this is the round brilliant itself. Its facet plan is set out in the anatomy of a round brilliant, and the measured standard we compare against is T57, the stone Tolkowsky published in 1919.
Materials
In moissanite the carré returns 82.25% for 87.01 Global with fire at 91.36. A step cut shows moissanite’s double refraction clearly, because the long clean facets give it nowhere to hide.
In cubic zirconia it returns 84.65% for 86.19 Global, leaking 11.15%.
Compare all three for this shape in the Index.
Trade-offs
Questions
The questions buyers actually ask, answered in full. Where the answer is ours to prove, the figure is measured on the Index; where it is an established gemological fact, it is stated as one.
A square step cut diamond, called a carré in the trade, is a square stone with sharp uncut corners and facets arranged in flat parallel steps rather than triangles and kites. It is the square counterpart of the emerald cut, and an Art Deco shape by origin.
Corners. An asscher is a square step cut with the corners cut off; a carré keeps them sharp. That makes the carré harder in outline and considerably more fragile, since the cut corners are exactly what protect an asscher from chipping.
Better than most fancy shapes. We measure 85.08% of useful light against the standard’s 92.28% and 84.11 Global against 88.61, a gap of 4.49 points. That places it first of the twenty-one jewellery cuts we publish, and it comes from a pavilion angle of 40°, close to what Tolkowsky solved for.
Not inherently, and this cut is the proof. What a step cut changes is the character of the return: broad flashes from long flat planes rather than fine sparkle from small triangles. Light return is decided by the pavilion angle, and a step cut with the right angle performs perfectly well.
The corners are. Four sharp uncut corners sit where diamond cleaves most readily, exactly as on a princess cut, and they need V-prongs or a bezel that covers them. Ordinary round prongs sit beside a corner rather than over it.
Higher than for a brilliant of the same size. The long open facets display inclusions plainly, so VS1 is a sensible floor and VS2 only on a stone verified eye-clean face-up.
No. GIA issues cut grades for round brilliants only. A report will usually describe the stone as a square step cut and record colour, clarity, carat, symmetry and polish.
Most often as a side stone or in geometric bands, particularly Art Deco pieces from the 1920s and 1930s and modern designs drawing on them. It is uncommon as a centre stone, which is why availability at larger sizes is limited.
Next
See the whole set on the jewellery cuts index, or the measured house and historic cuts in the cut registry.
Method
Monte-Carlo on exact facet geometry: 3,200 rays face-up plus 2,200 at 20° tilt, cosine-weighted from a 7° near-vertical cone. Useful light is what exits through the crown within 64° of vertical. The same protocol runs on every cut on this site, so the figures are comparable to each other.
They measure our reference geometry for the shape at the proportions listed above, not an average of stones on the market. A square cut to different proportions will read differently. Treat them as a like-for-like comparison between shapes, not as a grade for any individual stone.
Engine estimates, ±2 points, not lab-certified grades. We do not publish the Index symmetry axis on these pages: it scores facet regularity within each pavilion family, which is meaningful for a round brilliant and misleading for a shape whose pavilion is deliberately irregular.
78.42 here against the standard’s 71.82. The term is 100(1−e−n/45) on the count of facets that actually reach the surface, so it is a pure function of facet count and nothing else.