Cut registry › Jewellery cuts › Rectangle
Jewellery cuts · Step cut
Not the baguette you think.
Sold as a baguette, and carrying 45 facets where a classic baguette carries 25. That is not a small difference and it is not on any label.
The short version
A rectangle cut diamond is a rectangular step cut with square corners and facets arranged in flat parallel tiers, carrying 45 facets on our measurement.
The trade sells it as a baguette, alongside the classic straight baguette that carries only fourteen.
Definition
A classic straight baguette is a step cut stripped to almost nothing: fourteen facets, four square corners, and a plain rectangular outline. This stone shares the outline and the corners and adds a great many more facets.
The result behaves differently. More facets mean more separate returns, so it reads livelier and less mirror-like than a fourteen-facet baguette does. If you have ever seen a baguette that seemed to sparkle more than it should, this is usually why.
It is shorter than a classic baguette as well, at 1.51 against the straight baguette’s 1.97, which makes it a squatter, more rectangular stone rather than a long slim one.
The square corners are unprotected, exactly as on a baguette, which is why channel and bezel settings are the normal way to mount both.
Proportions
Trade description on the left, our measured reference stone on the right. There is no proportion standard for either kind of baguette.
| Measure | Commonly cited | Our reference stone | What it does |
|---|---|---|---|
| Length-to-width | 1.50 to 2.50 across baguettes | 1.51 | Shorter than the classic straight baguette. |
| Depth | 60% to 70% | 62.0% | The flat top, as a share of the width. |
| Table | 55% to 70% | 53.0% | Narrower than a classic baguette’s. |
| Pavilion angle | not commonly published | 33.5° | Shallow, and it leaks. See below. |
| Facets | 14 on a classic baguette | 45 | More than three times as many. |
Nothing on a report separates this from a fourteen-facet baguette. Both are rectangular step cuts, both are usually sold as calibrated goods by millimetre size rather than individually certified, and no laboratory issues a cut grade for either.
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 | 50.20% | 32.32% | 77.08 | 63.21 | 69.23 | −19.38 |
| Moissanite | 50.30% | 29.18% | 90.10 | 63.21 | 72.25 | −17.57 |
| Cubic zirconia | 51.00% | 38.55% | 87.30 | 63.21 | 69.21 | −22.56 |
| T57 standard, diamond | 92.28% | 1.88% | 78.85 | 71.82 | 88.61 | 0.00 |
The facet count is the story, and it is worth a great deal. This stone carries 45 active facets against the classic baguette’s 25, and scores 63.21 on scintillation against the baguette’s 42.62. Global rises to 69.23 from the baguette’s 56.56, a gain of over twelve points from facet count and proportion alone.
It still finishes 19.38 points behind the round brilliant standard, at 50.20% of useful light against 92.28%. Its pavilion sits at 33.5°, shallow by any measure, and it leaks 32.32% against the standard’s 1.88%.
So it is livelier than a baguette and nowhere near a brilliant. That is a fair description of what a heavily faceted step cut can do: adding facets buys sparkle, and only the pavilion angle buys light.
Where the light is: useful return along the length
Five equal bands from one end to the other. The rectangle returns 69.4% across the centre against 37.6% at the ends, a spread of 31.8 points, against the round-brilliant control’s 1.0. Like the emerald cut, a long step cut gives up its ends first.
Against the standard
Light return. 50.20% against the standard’s 92.28%, a Global gap of 19.38 points.
Against a classic baguette. 69.23 against 56.56, and 63.21 on scintillation against 42.62. Three times the facets, and it shows.
Sparkle character. 63.21 against the standard’s 71.82. Livelier than a baguette, calmer than any brilliant.
Durability. Square unprotected corners, so channel or bezel settings are the sensible mounting, as with any baguette.
Clarity and colour. Step facets hide nothing, and a rectangle has more of them than a baguette does but they are still open planes.
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 it returns 50.30% for 72.25 Global with fire at 90.10. A step cut shows moissanite’s double refraction plainly, because the long clean facets give it nowhere to hide.
In cubic zirconia it returns 51.00% for 69.21 Global.
Set it against the classic baguette 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 rectangle cut diamond is a rectangular step cut with square corners and facets in flat parallel tiers, carrying 45 facets on our measurement. It is normally sold as a baguette, alongside the classic straight baguette that carries only fourteen.
Facet count, mostly. A classic straight baguette carries 25 measured facets and scores 42.62 on scintillation; this stone carries 45 and scores 63.21. Global rises from 56.56 to 69.23. It is also shorter, at 1.51 against 1.97.
Most likely because it is not a fourteen-facet baguette. Scintillation on our engine is a pure function of how many facets reach the surface, and a rectangular step cut with 45 of them scores 63.21 against a classic baguette’s 42.62. Both are sold under the same word.
The square uncut corners are the vulnerability, exactly as on a baguette. Channel settings and bezels enclose those edges rather than leaving them proud, which is why both are the standard way to mount this shape.
Higher than a brilliant of the same size. Step facets are open planes with nothing to break up the view into the stone. It is more forgiving than a fourteen-facet baguette, because more facets mean more visual noise, but the principle holds.
Rarely. Like the baguette it is normally an accent: side stones, channels and bands. Its Global score of 69.23 places it seventeenth of the twenty-one jewellery cuts we publish, and it leaks 32.32%, so it is not competing with a brilliant for a solitaire.
No. GIA issues cut grades for round brilliants only, and most stones of this size are never individually certified in any case. They are bought as calibrated parcels matched to a millimetre size and a quality range.
Corners. An emerald cut has cut corners, which protect it and change the outline; a rectangle keeps them square. The emerald cut also carries more facets and a longer, more classical hall-of-mirrors effect, and we measure it at 70.48 Global against this cut’s 69.23.
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 rectangle 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.
63.21 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.