Rectangle Cut Diamond: the largest face for its weight we measure, level with the marquise
Brilliance 50 · Fire 77 · Scintillation 63 · in our census, where the T73 scores 93 · 78 · 80 in diamond
A plain rectangular step cut with square corners. It ties with the marquise for the largest face for its weight we measure in diamond, and returns about half of a round's light.
Rendered in our 3D Gemstone Simulator from the Rectangle Cut model, 1.00 ct, studio light.
Rectangle Cut Diamond
The rectangle is the emerald cut's simpler sibling: wide, straight steps and square corners, with nothing cropped. We measured a 45-facet model at a ratio of 1.506, its pavilion at 33.48° and its depth 62.0%.
In diamond it beats the T73 Round Brilliant on one score, by a margin no cut we measure exceeds (the marquise matches it), and trails it on four. Fire is level, 77 against 78, and its pavilion is as regular as a round's: Symmetry 100.
Is a rectangle cut diamond worth it? Pros and cons
Compared with the T73 Round Brilliant in diamond.
A difference counts from 3 points (Brilliance, Fire, Tilt, Leakage), 5 (Scintillation,
Symmetry), 4% (face-up size per carat) or 5% (weight); Tilt counts as a pro only for a stone within
5 points of the brilliance it is compared with. How we measure.
All eight scores against the T73
At a glance: the Rectangle Cut in diamond (white) against the T73 Round Brilliant in diamond (dashed): solid white where
it reaches further, hatched where it falls short. Each pro and con is explained, with pictures, below.
Against the T73 Round Brilliant in diamond: level on 2, behind on 6.
Global69, the comparison 90, difference −21
Brilliance50, the comparison 93, difference −43
Fire77, the comparison 78, difference −1
Scintillation63, the comparison 80, difference −17
Spread100, the comparison 100, difference 0
Symmetry100, the comparison 100, difference 0
Shape-norm66, the comparison 100, difference −34
Tilt85, the comparison 92, difference −7
Face-up light census, a different measure from the Cut Grading Tool; Spread and Shape-norm above 100 sit on the ring. Spread is the census's estimate from depth alone; the face-up size in the pros and cons is measured from each model's outline.
Level with the marquise for the largest face for its weight we measure
Face-up size 121 against 100 for the T73 Round Brilliant in diamond (T73 = 100): 21% more face-up area for the same weight
Set beside the T73 at the same weight, the rectangle's outline covers about a fifth more area. Only the marquise matches it among the cuts we measure in diamond; the emerald cut, its cropped-corner cousin, reaches 105.
Rectangle Cut · 7.65 x 5.08 mm at 1.00 ct · Face-up size 121
T73 Round Brilliant · 6.48 mm at 1.00 ct · Face-up size 100
Both stones weigh 1.00 ct in diamond and are drawn to the same scale in millimetres, from each cut's own model. Face-up size is the outline's area per carat, with the T73 at 100: a deeper stone, or a rounder outline, spreads less area for its weight.
Brilliance 50 against 93 for the T73 Round Brilliant in diamond: 43 points lower
Broad steps send light back up at fewer angles than a brilliant's many small facets. The pavilion figure, 33.48°, is under the 38.9° guide minimum we use for rounds, and we have not measured a steeper rectangle.
Rectangle Cut in diamond · Brilliance 50
T73 Round Brilliant in diamond · Brilliance 93
Red, green and blue = light returning to the eye; grey = light leaving through the pavilion. This is the head-on view; the Brilliance score averages a wider cone of light, so the score can differ from what one picture shows.
What helps: With cropped corners, the Emerald Cut Diamond returns 55; with the same face for its weight and more light, the Marquise Cut Diamond returns 64.
Leakage 32 against 2 for the T73 Round Brilliant in diamond: 30 points higher
The census loses 32% of the rectangle's light out of the back, against 2% for the T73. Only four cuts we measure in diamond lose more.
Rectangle Cut in diamond · Leakage 32
0° · 35% leak
10° · 35% leak
20° · 37% leak
30° · 45% leak
T73 Round Brilliant in diamond · Leakage 2
0° · 4% leak
10° · 2% leak
20° · 9% leak
30° · 14% leak
Each frame is the Light Return map with the stone tilted away from you by the angle shown; grey is light leaving through the pavilion. The share under each frame is that picture's own.
Scintillation 63 against 80 for the T73 Round Brilliant in diamond: 17 points lower
It has 45 facets, most of them long steps, against the T73's 73. Scintillation rises with the facets that reach the surface, so the rectangle also trails the emerald cut, which has more of them and scores 72.
Scintillation follows the number of facets: more facets, more and smaller flashes as the stone moves. Count the facets in each crown. Drawn from each cut's own model.
What helps: Steps set this. The Marquise Cut Diamond, just as large for its weight, scores 86.
Tilt 85 against 92 for the T73 Round Brilliant in diamond: 7 points lower
At a 20° tip it holds 85 of its face-up light, the T73 92. The emerald cut keeps 83: the two rectangles behave much alike as they move.
Rectangle Cut in diamond · Tilt 85
0° · 35% leak
10° · 35% leak
20° · 37% leak
30° · 45% leak
T73 Round Brilliant in diamond · Tilt 92
0° · 4% leak
10° · 2% leak
20° · 9% leak
30° · 14% leak
Tilt is how much of its own face-up light a stone keeps when tilted. Each frame is the Light Return map with the stone tilted away from you by the angle shown; grey is light leaving through the pavilion. The share under each frame is that picture's own.
What helps: To hold more at an angle without giving up light, the Old European Cut Diamond keeps 93.
Choose the rectangle when the most face for the weight matters and the design calls for straight lines: side stones, bars and minimalist settings. Expect about half a round's light and a slower, broader sparkle.
If you can give up some face-up size for light, the Emerald Cut Diamond is the closer step cut. If the outline need not be a rectangle, the Marquise Cut Diamond matches its face-up size with more light, more fire and less leakage.
Rectangle Cut Diamond: questions
Rectangle or emerald cut diamond?
The emerald cut returns more light (55 against 50) and more fire (87); the rectangle faces up larger for its weight (121 against 105) and has the more regular pavilion.
Does a rectangle cut diamond look bigger for its weight?
Yes: Face-up size 121 against 100 for the T73, level with the marquise at the top of our diamond figures.
Is a rectangle step cut diamond brilliant?
Less than a round: Brilliance 50 against 93, and 32% of its light lost through the back.
What does a 6.5 mm wide rectangle cut diamond weigh?
2.10 ct for a stone 6.5 mm across and 1.506 times that in length.
Get the Rectangle Cut files
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Rectangle Cut 3D files
The Rectangle Cut as exact geometry: 45 planar facets, real-world scale, ready for CAD,
rendering, printing and casting.
