Emerald vs Asscher Cut Diamonds: Shape, Sparkle, Size and Settings Compared

What is the difference between emerald and Asscher cut diamonds?

Both shapes are step cuts. Instead of the triangular and kite-shaped facets of a round brilliant, a step cut has long, flat facets arranged in rows that run parallel to the edge of the stone, like the steps of a staircase. Our guide to the whole step cut family, from emerald to baguette and carré explains how these rows handle light. Both shapes also have their corners cut off, which is why they look like octagons up close.

The headline difference is the outline. An emerald cut is a rectangle, longer than it is wide. An Asscher cut is a square. But the Asscher is not simply a square emerald. It is usually cut with a higher crown (the top part above the girdle), a smaller table (the large flat facet on top), a deeper pavilion (the lower part) and larger corner facets. Those changes give it a different look: an emerald shows broad flashes of light like a row of mirrors, while an Asscher draws your eye into the centre through a pattern of concentric squares.

On a GIA grading report you will often see an Asscher described as a square emerald cut, because the lab grades by outline and facet style rather than by trade names. That is one reason the two get confused online. For the full story on each shape on its own, see our complete emerald cut diamond guide and the Asscher cut diamond guide. Any term here you have not met before is also explained in the GemTrove jewellery glossary.

How are emerald and Asscher cuts faceted?

Most emerald cuts have 57 or 58 facets: typically three rows of steps on the crown, three or more rows on the pavilion, a table and, on some stones, a culet (a tiny flat facet at the very bottom). Cutters vary the number of pavilion rows, and some modern emeralds add extra steps for a little more sparkle. The classic Asscher also has about 58 facets, but its rows are arranged more steeply so the corners reflect into the middle of the stone.

The Asscher name goes back to the early twentieth century and the Asscher family of diamond cutters in Amsterdam. Old Asschers were cut by eye and vary a lot; modern Asschers are more uniform. You may also see the Royal Asscher, a trademarked variation with more facets (commonly quoted as 74) that adds extra steps for more brightness. It is a branded version of the shape rather than a separate grade.

The emerald cut takes its name from the gemstone. Lapidaries (gem cutters) used step cuts on emeralds because emerald is brittle and the cut corners reduce the risk of chipping. The same logic helps diamonds: diamond is 10 on the Mohs hardness scale, but it can still chip along cleavage planes, and a cut corner is much tougher than a sharp one. Both shapes are good choices for everyday wear for that reason.

What ratio should an emerald or Asscher cut have?

The length-to-width ratio is the stone's length divided by its width, both taken from the measurements on the report. A ratio of 1.00 is a perfect square. This single number is the clearest way to tell the two shapes apart, and it changes the look of an emerald dramatically.

For an Asscher, look for a ratio of 1.00 to about 1.05. Beyond that, the stone starts to look like a rectangle that is not quite sure what it is, and the windmill pattern loses its balance. For an emerald, most people choose 1.30–1.50, and our page on choosing the right emerald cut ratio walks through each range with examples. If you like the slim, modern look, our guide to elongated emerald cuts above 1.50 shows how they wear.

Proportions matter as much as outline. As a rough guide, many well-cut emeralds sit at a total depth of about 61–68% with a table of about 61–69% of the width. Asschers are usually cut a little deeper and with a noticeably smaller table, often around 52–65%. GIA gives neither shape an overall cut grade, so you judge the cut from these numbers, the polish and symmetry grades, and most of all the way the stone looks in a video.

Emerald vs Asscher cut: which has more sparkle?

Neither shape sparkles like a round brilliant, and that is the point. Step cuts trade the scattered, fiery sparkle of a brilliant for broad flashes of light and dark that switch on and off as the stone moves. People who choose them usually describe the look as clear, calm or architectural.

• Emerald cut: the long steps create the hall-of-mirrors effect, where reflections line up down the length of the stone like facing mirrors. Our page on the emerald cut hall-of-mirrors effect shows what a good one looks like.
• Asscher cut: the steep steps and large corners create a windmill pattern, four arms of light and dark radiating from the centre, framed by concentric squares. See the Asscher windmill pattern explained for what to look for in photos.
• Brightness: the Asscher's higher crown and smaller table tend to give a little more contrast and depth; the emerald's larger table shows more of the stone's interior.

The fault to watch for in both is windowing: a washed-out, see-through area in the middle of the stone where light passes straight out the bottom instead of bouncing back to your eye. It is caused mainly by a pavilion that is too shallow. Emerald cuts, with their bigger tables and shallower cutting, show it more often; a well-cut Asscher's depth usually prevents it. Our guide to spotting windowing in an emerald cut explains how to check a video for it.

If you want the outline of an emerald but more sparkle, the radiant cut uses the same cropped-corner rectangle with brilliant-style facets underneath. For a square with more fire than an Asscher, compare the princess and Asscher, square for square, or the softer Asscher against the rounded cushion cut.

Emerald vs Asscher cut: which looks bigger for its carat weight?

The emerald does. Because it is spread out into a rectangle and usually cut with a larger table and a shallower pavilion than an Asscher, it shows more surface area face-up (the size you see from above). An Asscher holds more of its weight in its deep pavilion and high crown, so at the same carat it looks smaller on the hand.

At 1 carat, a typical emerald covers about 35 mm² of outline against about 30 mm² for an Asscher, roughly 15% more before allowing for the cut corners. The emerald's length also makes it look larger on the finger: a 7 mm stone running along the finger reads bigger than a 5.5 mm square, even though the Asscher is wider. These are typical figures only; always compare the millimetre measurements on the report, not just the carat weight.

The trade-off works the other way too. If you want a stone that sits proud and looks deep and glassy, the Asscher's extra depth is part of its appeal. Many people who love Art Deco jewellery prefer it for exactly that reason.

What clarity and colour do emerald and Asscher cuts need?

Step cuts are the most revealing diamond shapes. A brilliant cut breaks light into hundreds of small flashes that hide inclusions (internal features); a step cut's broad, open facets act like a window into the stone. That applies to both shapes, though the emerald's larger table shows a little more.

• Clarity: most people choose VS2 or better, and many choose VS1. A carefully selected SI1 can work if the inclusions sit near the edge rather than under the table.
• Where inclusions sit: anything in the centre of the table is easy to see. Small features near a corner or under the step facets are much less visible.
• Colour in white metal: G–H for an emerald; G or better for an Asscher, because its depth can concentrate body colour in the corners.
• Colour in yellow or rose gold: H–I can look white, as the warm metal masks a slight tint.

For the Asscher in particular, our Asscher clarity grades, inclusion by inclusion guide shows which types of inclusion matter and where. The same principles apply to emeralds: look at the plotting diagram on the report, which maps every inclusion, and check it against the video.

How do emerald and Asscher cuts compare side by side?

In short, choose the emerald if you want the most visible size for your budget and a long, elegant line on the finger. Choose the Asscher if you prefer a square, compact stone with depth and a vintage character. To see both alongside every other outline, start with our overview of all the main diamond shapes.

What is the best setting for an emerald or Asscher cut ring?

Both shapes have four cut corners, which are tougher than the sharp corners of a princess cut, but they are still the most exposed points. The setting's job is to hold the stone securely at those corners without hiding the clean lines that make step cuts attractive.

• Four claws: the classic choice for both. On an emerald, claws usually sit on the cut corners; on an Asscher, placing them at the corners keeps the square outline crisp. Some people set an Asscher turned 45 degrees, with claws still at the corners, so it reads as a diamond-shaped (rhombus) outline.
• Double claws: two claws at each corner add security and look neat on larger emeralds.
• Bezel: a thin metal rim around the edge. Very secure and modern, and it suits the geometric look of both cuts.
• Halo: a frame of small diamonds. A halo makes an Asscher look noticeably larger, which offsets its smaller face-up size.
• Side stones: tapered baguettes or trapezoids continue the step-cut look; a three-stone ring with smaller step cuts either side is a common Art Deco style.

For worked examples, see our guides to ring settings that suit an emerald cut and setting styles that frame an Asscher. Metal colour matters too: platinum and white gold suit the icy look of a high-colour step cut, while yellow gold gives an Asscher a warm vintage feel.

How much do emerald and Asscher cut diamonds cost in Australia?

Emerald and Asscher cuts are available in both natural and lab-grown diamond. Lab-grown diamonds are real diamond, with the same hardness (Mohs 10) and refractive index (about 2.42) as natural, but grown in a laboratory rather than mined. They cost much less than natural and are easy to find in larger sizes. Both types should come with an independent grading report from a lab such as GIA or IGI that states clearly whether the diamond is natural or laboratory-grown.

These are broad ranges only; prices move with the market and with exact grades. Both shapes usually cost less per carat than a round of the same weight, colour and clarity, partly because step cuts keep more of the rough crystal. Asschers are less common than emeralds, so a well-cut natural Asscher can cost slightly more. Because both shapes need higher clarity, a good step cut can end up similar in price to a brilliant shape at a lower clarity grade.

How do you choose between an emerald and Asscher cut? Step by step

1. Decide on the outline. Rectangle (emerald) for length and face-up size, or square (Asscher) for depth and a vintage look.
2. Check the ratio. Divide length by width on the report: 1.00–1.05 for an Asscher, 1.30–1.50 for a classic emerald, higher if you want elongated.
3. Check depth and table. Emerald around 61–68% depth; Asscher with a smaller table, usually under about 65%.
4. Watch a 360° video. Look for a clear hall of mirrors or windmill pattern, and for windowing in the centre.
5. Check clarity where it counts. Use the plotting diagram; the centre of the table should be clean.
6. Compare millimetres, not just carats. Use the size table above to see how each will look on the hand.
7. Plan the setting. Make sure claws or a bezel protect all four corners before you commit.