Cut registry › Jewellery cuts › Hexagon
Jewellery cuts · Step cut
Six sides.
The hexagon is chosen almost entirely for its outline, and it is the one shape here where that is obviously the right reason. The figures explain what the outline costs.
The short version
A hexagon cut diamond is a six-sided step cut, with facets arranged in flat parallel tiers around a regular or slightly elongated hexagonal outline.
It is a modern geometric shape rather than a historic one, and it has become a staple of alternative and architectural engagement ring design.
Definition
The hexagon belongs to the step-cut family alongside the emerald, asscher, baguette and octagon. Its six sides give it a honeycomb geometry that tessellates: hexagons sit against each other and against triangles without gaps, which is why cluster and mosaic settings use them.
It is cut both as a step cut and, less often, with brilliant faceting. Our reference stone is the step cut, which is the form the trade means by default. If you are comparing prices, ask which you are looking at.
Practically, its six corners are shallow rather than sharp, so it is more robust than a princess or a carré and less robust than an octagon or a round.
Proportions
Trade description on the left, our measured reference stone on the right. There is no standardised proportion set for a hexagon, which is common among modern geometric shapes.
| Measure | Commonly cited | Our reference stone | What it does |
|---|---|---|---|
| Outline | regular or elongated hexagon | regular hexagon | Six sides. |
| Length-to-width | 1.00 to 1.20 | 1.16 | Elongated hexagons are common and purely aesthetic. |
| Depth | not standardised | 61.0% | The flat top, as a share of the width. |
| Table | not standardised | 60.0% | Large, as on any step cut. |
| Pavilion angle | not commonly published | 50.2° | Shallow, and it leaks. See below. |
| Facets | varies with tier count | 37 | Counted as facets that actually reach the surface. |
No laboratory issues a cut grade for a hexagon. Because the shape has no proportion standard at all, two hexagons of the same weight and outline can perform very differently, and there is no figure on a report that will tell you which is which.
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 | 58.18% | 24.23% | 84.83 | 56.05 | 75.93 | −12.68 |
| Moissanite | 57.13% | 26.42% | 96.77 | 56.05 | 77.74 | −12.08 |
| Cubic zirconia | 63.76% | 21.24% | 83.82 | 56.05 | 77.92 | −13.85 |
| T57 standard, diamond | 92.28% | 1.88% | 78.85 | 71.82 | 88.61 | 0.00 |
Our reference hexagon returns 58.18% of entering light usefully and leaks 24.23%, for 75.93 Global against the standard’s 88.61. That leak figure is high, and its cause is the pavilion: at 50.2° it sits well below what a diamond’s critical angle wants, so a large share of the light entering the stone leaves through the bottom.
It carries 37 active facets, among the fewest of the jewellery cuts, for 56.05 on scintillation against the standard’s 71.82. What it does well is fire, at 84.83 against 78.85, because a small number of large facets throws wide, well-separated spectra.
Read this as a measurement of a shallow reference stone, not a verdict on hexagons. The shape has no proportion standard, so a hexagon cut with a proper pavilion angle will not read like this. The useful lesson is that on a shape nobody standardises, the pavilion angle is doing all the work and nothing on the report will tell you what it is.
Its Index tilt figure sits at the scale ceiling of 100. On a stone returning 58.18% face-up, that means there was little left to lose rather than that the cut is stable.
Where the light is: useful return across the face
Five equal bands across the stone, each returning ray binned by where it leaves the crown. The hexagon returns 68.2% at the centre against 65.1% at the edges, against the round-brilliant control’s 99.1% and 98.1%.
Against the standard
Light return. 58.18% against the standard’s 92.28%, with the pavilion-angle caveat above attached.
Fire. 84.83 against 78.85, and the hexagon wins. Few large facets throw broad, well-separated colour.
Sparkle. 56.05 against 71.82, on 37 facets against 57.
Durability. Six shallow corners: safer than a princess or a carré, less safe than an octagon or a round.
Design. The reason people choose it. Hexagons tessellate with each other and with triangles, so they suit cluster, mosaic and architectural settings that no round can do.
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 hexagon returns 57.13% for 77.74 Global with fire at 96.77. A high-dispersion material and a small number of large facets is a strong combination for colour, and it partly compensates for the light this geometry gives up.
In cubic zirconia it returns 63.76% for 77.92 Global.
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 hexagon cut diamond is a six-sided stone, most commonly cut as a step cut with facets in flat parallel tiers around the outline. It is a modern geometric shape rather than a historic one, and it is a staple of alternative and architectural engagement ring design.
Reasonably. Its six corners are shallow rather than sharp, which makes it more robust than a princess or a carré and less robust than an octagon or a round brilliant. A setting that covers the corners is sensible but not essential.
Our reference hexagon returns 58.18% of entering light against the standard’s 92.28%, for 75.93 Global against 88.61. It beats the standard on fire, 84.83 against 78.85, because a small number of large facets throws wide, well-separated spectra.
Because our reference stone has a shallow pavilion, at 50.2°, well below what diamond’s critical angle wants, so light entering the stone exits through the bottom. That is a property of this geometry rather than of hexagons as a class. The shape has no proportion standard, so a hexagon cut deeper will read very differently.
No, and that is the single most important thing to know about the shape. Two hexagons of the same weight and outline can perform very differently, no laboratory issues a cut grade for the shape, and nothing on a report records the pavilion angle that decides the result. Judge on video.
The faceting inside the same outline. A step cut has flat parallel tiers and throws broad slow flashes; a brilliant version has triangles and kites and produces finer sparkle. The step cut is the default and the one our figures describe, so ask which you are being shown.
No. GIA issues cut grades for round brilliants only. A hexagon report will record colour, clarity, carat, symmetry and polish and describe the shape, with nothing about light performance.
Because they tessellate. Hexagons sit flush against each other and against triangles with no gaps, which lets a designer build a continuous mosaic surface. Round and oval stones cannot do that, and it is the main reason the shape has become popular in architectural design.
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 hexagon 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.
56.05 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.