Hexagonal Cut Diamond Guide: Facets, Ratio, Colour and Settings

What is a hexagonal cut diamond?

A hexagonal cut diamond is a diamond cut with a six-sided outline. Looked at from above (face-up), it has six straight edges, called flats, meeting at six corners. On a perfectly regular hexagon every side is the same length and every corner is 120°, the same angle you see in a honeycomb. Many hexagons are stretched along one axis, giving an elongated hexagon with two long sides and four shorter ones.

Hexagons are not one of the standard shapes that cutters produce in large numbers, like rounds, ovals or emeralds. They sit in the specialty group of geometric cuts, which you can see alongside every other shape in the full list of 34 diamond cuts. Small hexagonal stones were used in Art Deco jewellery of the 1920s and 1930s, often fitted tightly together as accents, and the shape has come back into fashion for engagement rings that want clean lines without a square or a rectangle.

Diamond is 10 on the Mohs scale of hardness and has a refractive index (how strongly it bends light) of about 2.42. That is why even simple facet patterns look bright in diamond. Hardness is not toughness, though: diamond can still chip along its cleavage planes if a thin edge or corner takes a hard knock. A hexagon's corners are wider than many geometric shapes, which helps, but they still need protecting.

The hexagon belongs to the same geometric family of shield, kite and pentagon cuts, all defined by straight edges and distinct corners. If a term here is new to you, our glossary of jewellery terms explains it in plain language.

Step cut or brilliant: how are hexagon diamonds faceted?

Most hexagonal diamonds are step cut. A step cut uses long, flat, parallel facets arranged in rows (steps) that follow the outline of the stone, the same idea as an emerald or Asscher cut. A step-cut hexagon has a large flat table (the top facet) shaped like a smaller hexagon, with two or three rows of steps on the crown above the girdle (the outer edge) and several more on the pavilion (the lower half).

The look is calm and architectural. Instead of the scattered sparkle of a round, you see broad flashes of light and dark that move across the steps as the stone turns. This is often called the hall-of-mirrors effect. Facet counts vary with how many steps the cutter adds, but most hexagons sit somewhere around 30 to 50 facets.

You will also find hexagonal modified brilliants, which use triangular and kite-shaped facets like a round brilliant, fitted to a six-sided outline. They sparkle more, hide inclusions better and look a little less crisp at the edges. A small number of hexagons are rose cut, with a flat base and a domed top of triangular facets; our comparison of how rose cuts differ from brilliant cuts explains that softer, glowing look.

Grading reports describe the stone as they see it, for example 'hexagonal step cut' or 'hexagonal modified brilliant'. Check this line first, because it tells you more about how the stone will look than the shape name alone.

What is the ideal ratio for a hexagonal diamond?

The length-to-width ratio compares the stone's longest measurement with its width. Divide the length by the width on the grading report. A hexagon is a special case: measured corner to corner, a perfectly regular hexagon is about 1.15 times longer than it is wide flat to flat. So a regular hexagon never shows a ratio of 1.00, even though it looks perfectly balanced.

An elongated hexagon can look a lot like a lozenge cut, a slim four-sided cousin, so look closely at the sides. On a hexagon two long parallel flats run along its length and each end is formed by two short sides; a lozenge has only four sides, meeting in a corner at its widest point.

GIA does not give fancy shapes such as hexagons an overall cut grade, so you judge the cut from the proportions, the polish and symmetry grades and, above all, how the stone looks. As a rough guide, many attractive step-cut hexagons have a total depth of about 60–72% and a table of about 60–72% of the width. Too shallow and the centre looks glassy and see-through; too deep and the stone carries hidden weight and faces up small.

How big does a hexagonal cut diamond look? Size chart

Step cuts tend to carry a little more weight in the pavilion than brilliants, so a step-cut hexagon faces up slightly smaller than a round of the same carat weight. The figures below are typical for a regular step-cut hexagon at a ratio of about 1.15. Treat them as a starting point and always compare the millimetre measurements on the report.

An elongated hexagon of the same weight looks longer on the finger and can appear a little larger, because the eye reads length. For a wider look at how outline affects face-up size across shapes, compare the main cuts side by side.

Small hexagons, from about 0.05 to 0.30 carat, are popular in clusters and eternity bands because the flat sides can sit edge to edge with very little metal showing between them.

What colour and clarity suit a hexagon diamond?

A step cut gives you a clear window into the stone. That is part of its appeal, but it also means inclusions (internal features) are easier to see. In a step-cut hexagon, most people choose VS2 or better, and VS1 for stones over about 1.5 carats, where the larger table makes everything more visible. A hexagonal modified brilliant can often be eye-clean (no inclusions visible without magnification at normal viewing distance) at SI1.

Step cuts also show body colour a little more than brilliants, especially at the corners, where light concentrates. In white gold or platinum, G–H colour usually looks white; if you notice warmth easily, go to F or G. In yellow or rose gold, I or J can look just as white because the metal warms the whole ring.

• Step cut, white metal: G–H colour, VS2 or better.
• Step cut, yellow or rose gold: I–J colour, VS2 or better.
• Modified brilliant: G–H colour, SI1 if eye-clean.
• Avoid: feathers (small internal cracks) reaching a corner, and dark inclusions under the table.

Ask to see the plotting diagram on the report, which maps where each inclusion sits, and check a 360° video in steady light. In a step cut, an inclusion under the table is often reflected in the steps, so one small crystal can appear several times.

Are hexagon diamonds durable enough for everyday wear?

Yes, with the right setting. A hexagon's corners are about 120° on a regular stone, which is much wider than the 90° corners of a princess cut and far wider than the trilliant's 60° points. The wider the angle, the more diamond there is behind the corner, and the less likely it is to chip.

Elongated hexagons need a little more care. If the stone is stretched by narrowing it, the two corners at the tips become sharper than 120°, so those are the ones to protect first. A thin girdle at any corner is also a weak spot; the report describes girdle thickness, and 'thin to medium' or 'medium' is safer than 'extremely thin'.

What is the best setting for a hexagon diamond engagement ring?

The setting has two jobs: protect the corners and keep the straight edges looking crisp. The common options for a hexagon diamond engagement ring:

• Six claws: one at each corner. This protects every corner and frames the shape. V-claws or flat-tipped claws suit geometric stones better than round beads.
• Bezel: a thin hexagonal rim of metal around the whole stone. The most secure option, very modern, and it emphasises the six sides.
• Half-bezel or compass claws: metal on two opposite sides or at the main corners, leaving more of the outline open.
• Halo: a row of small diamonds following the hexagon. It makes the centre look larger and shields the girdle.
• Three-stone: trapezoid side stones can line up with the hexagon's flats for a clean, continuous line, while half moon side stones soften it. Slim bullet cut accents point neatly towards the centre.

Think about orientation too. A regular hexagon can be set with a corner pointing towards your fingertip or with a flat edge facing it; the two looks are surprisingly different, so try both before you decide. Elongated hexagons can sit north-south along the finger or east-west across it.

For the wedding band, a hexagon has an advantage: when an elongated hexagon is set east-west, its long flat sides face the band, so a straight band can usually sit flush if the setting is low enough. A regular hexagon set corner-to-band may need a contoured or notched band.

How does a hexagon compare with other geometric diamond cuts?

If you like the honeycomb look but want even softer corners, octagonal cut diamonds add two more sides and sit closer to a circle. The five-sided pentagonal cut gives a less familiar outline with one corner pointing up. For a shape with a clear point at one end, look at the shield cut, the kite cut diamonds page or the calf's head cut, all of which work well as centre stones or side stones.

At the sharper end of the range are triangular step and brilliant cuts, which need careful protection at three points. Square shapes with trimmed corners, such as the Flanders cut with its clipped corners, sit somewhere between a princess and an octagon.

How much does a hexagonal cut diamond cost, natural or lab-grown?

Hexagons are cut from both natural and laboratory-grown diamond, and the two look identical to the eye. Lab-grown diamonds are real diamond with the same hardness and refractive index, grown in a laboratory rather than mined. They cost much less than natural diamonds, and because lab-grown cutters produce more specialty shapes, a lab-grown hexagonal diamond is usually easier to find in larger sizes. Natural hexagons are scarce, particularly above 1 carat, and finding a well-matched pair for earrings can take time.

These are broad ranges only; prices move with the market and with exact grades. A hexagon usually costs less per carat than a round of the same weight, colour and clarity, because demand is lower. Within hexagons, the price is driven by carat, colour, clarity and how cleanly the corners and steps are cut. Rarity can work both ways: there are fewer buyers, but there are also fewer well-cut natural stones to choose from.

How do you choose a hexagonal cut diamond? Step by step

1. Read the report. Confirm the shape description (step cut or modified brilliant), measurements, colour, clarity, polish, symmetry and whether the diamond is natural or lab-grown.
2. Work out the ratio. Divide length by width. About 1.15 is a regular hexagon; 1.25–1.70 is elongated.
3. Check the sides. In a regular hexagon the six flats should look equal; in an elongated one the two long sides should be parallel and the four short sides matched.
4. Check clarity for the cut. VS2 or better for a step cut; a brilliant may be eye-clean at SI1.
5. Inspect every corner. Look for a very thin girdle or feathers reaching the edge.
6. Compare face-up size. Use the millimetre measurements, not just the carat weight.
7. Plan the setting and band. Choose six claws, a bezel or a halo, decide on orientation, and check how the wedding band will sit before you commit.