Step-Cut Diamonds Explained: The Complete Emerald & Asscher Guide
What Are Step-Cut Diamonds?
When most people picture a diamond, they think of the round brilliant — that classic dome of triangular facets firing light in every direction. Step-cut diamonds are the opposite. Instead of dozens of angled facets designed to scatter light, step cuts use long parallel facets arranged in concentric rectangles or squares that descend toward the centre of the stone like steps in a staircase. The result is a completely different visual character: deep, architectural, and quietly luminous rather than flashy.
The two most popular step cuts are the emerald cut and the asscher cut. They share the same facet philosophy but have distinct silhouettes, and each suits a different aesthetic. If you are drawn to jewellery that feels more Old Hollywood than modern sparkle, a step cut is almost certainly the right direction.
The Emerald Cut: Elongated Elegance
The emerald cut takes its name from the way gemologists originally cut emeralds — the parallel steps reduce pressure during polishing, which protects a fragile stone. Jewellers quickly realised the same approach created a stunning diamond silhouette, and the emerald cut has remained a staple of fine jewellery ever since.
The defining feature of the emerald cut is its elongated rectangular outline with cropped corners. Most emerald cuts have a length-to-width ratio between 1.3 and 1.75, with 1.4 to 1.5 being the sweet spot preferred by most clients. The cropped corners are not just decorative — they protect the points of the diamond from chipping and make setting the stone much easier.
Because of its length, an emerald cut tends to flatter the finger dramatically. The elongated shape draws the eye up and down rather than across, which makes the finger appear longer and more slender. A 1.5ct emerald cut often looks larger and more prominent on the hand than a 1.5ct round brilliant of the same carat weight.
The Asscher Cut: Vintage Geometry
The asscher cut was developed in 1902 by the Royal Asscher Diamond Company in Amsterdam and enjoyed its first wave of popularity during the Art Deco period. It was revived in the early 2000s and has been growing steadily in popularity since. Today it is one of the most requested cuts at Diamond Ateliers.
Where the emerald cut is rectangular, the asscher is nearly square — most fall between a 1.0 and 1.05 length-to-width ratio. The asscher also tends to have a slightly higher crown and more stepped facets than an emerald cut, which gives it an even deeper hall-of-mirrors effect. When you look straight down into a well-cut asscher, you see a series of concentric squares pulling you into the centre of the stone — it is unlike any other diamond shape.
The modern asscher cut (sometimes called the Royal Asscher) has 74 facets compared to the original 58, producing more brilliance while keeping the signature geometric depth. When choosing an asscher, always ask whether you are looking at a standard or Royal Asscher cut, as the difference in visual quality is noticeable.
Emerald vs Asscher: How to Choose
Both cuts share the same step-cut character, so the choice often comes down to finger shape and personal aesthetic preference.
The emerald cut tends to suit people who prefer a more classic, timeless ring that reads as elegant rather than statement-making. It works beautifully in a simple solitaire setting and pairs exceptionally well with a thin, plain band. It also tends to look flattering on a wider range of finger shapes because of its elongating effect.
The asscher cut appeals to clients who love the Art Deco aesthetic — strong geometry, symmetry, and vintage character. It tends to look more distinctive and slightly bolder on the hand, especially in a bezel setting that emphasises its square silhouette. If you are drawn to architectural jewellery and vintage rings, the asscher is worth serious consideration.
Our advice at Diamond Ateliers: bring in a few inspiration images and let us show you both in person before you decide. The difference in personality between the two is much clearer when you see them side by side in natural light.
What Quality Factors Matter Most in Step-Cut Diamonds?
This is the most important thing to understand about step-cut diamonds: they are far less forgiving than brilliant cuts. Because step facets are broad and transparent rather than reflective and angular, they do not hide inclusions or colour in the way a round brilliant does. Anything inside the stone — a feather inclusion, a cloud, a crystal — is much more visible to the naked eye.
Here is what to pay close attention to:
Clarity
For an emerald or asscher cut, we recommend a minimum of VS2 clarity and ideally VS1 or above. With a round brilliant, you can sometimes go as low as SI1 and still have an eye-clean stone. With a step cut, SI inclusions are frequently visible without magnification. This is non-negotiable — a beautiful step cut with a visible inclusion in the table is never going to look right.
Colour
Step cuts also show colour more clearly than brilliant cuts. The long flat facets act like windows, and if the stone has a yellow or brownish tint, you will see it. For a white gold or platinum setting, aim for G colour or better. If you are setting in yellow gold, H or I can still look beautiful because the warm setting masks any body colour in the stone.
Cut Quality
Unlike round brilliants, step cuts are not graded for cut by the GIA — the certificate will simply say "emerald cut" or "asscher cut" without an overall cut grade. This means you need to evaluate the cut yourself (or have an expert do it for you). Key things to look for: symmetrical step alignment, a well-proportioned table, and a uniform culet that sits exactly in the centre of the stone. Off-centre culets and uneven steps are common in lower-quality step cuts and ruin the hall-of-mirrors effect.
The "Bowtie" in Emerald Cuts
Many elongated step cuts — including emerald cuts — can show a dark bowtie shadow across the centre of the stone when viewed face-up. A minor bowtie is acceptable and barely noticeable in a well-cut stone; a strong bowtie is a significant flaw that will always be visible on the hand. When buying an emerald cut, always view it face-up in normal lighting before committing.
Step-Cut Diamonds and Lab Diamonds
Step cuts are an excellent candidate for lab-grown diamonds. Because the quality bar for clarity and colour is higher — you genuinely need a cleaner, whiter stone — the cost difference between natural and lab becomes more significant. A natural VS1, G-colour emerald cut at 1.5ct will cost considerably more than an equivalent lab diamond, and the quality difference is invisible to the naked eye. Many of our clients specifically choose lab diamonds for step-cut designs because the budget saving allows them to go up a size or invest in a more intricate setting.
Setting Styles for Emerald and Asscher Cuts
The right setting can transform a step-cut diamond. Here are the styles we work with most often at Diamond Ateliers:
Solitaire with a thin band — the most popular choice. A fine platinum or 18k white gold band keeps the focus entirely on the stone. Classic, timeless, and never dates.
Bezel setting — a sleek metal rim surrounds the entire perimeter of the stone. This is a beautiful choice for asscher cuts in particular, as the bezel reinforces the square silhouette. It also offers the best protection for the stone's corners.
East-West setting — for the emerald cut, setting the stone horizontally (rotated 90 degrees) creates an unexpectedly modern look that sits low on the finger and feels very contemporary.
Three-stone setting — flanking an emerald cut with two smaller step-cut or trillion side stones is a timeless combination. The symmetry of the steps all pointing in the same direction creates a very clean, cohesive look.
Hidden halo — a row of micro pavé diamonds tucked beneath the main stone adds brilliance from the side profile without interrupting the clean face-up view of the step cut.
How We Design Step-Cut Rings at Diamond Ateliers
Every ring we create starts with a consultation — no pressure, no rush. We source the diamond first, choosing a stone that genuinely meets the clarity and colour standards a step cut demands. We then design the setting around your lifestyle and aesthetic: whether you prefer a minimal solitaire, a vintage-inspired asscher with engraved shoulders, or a modern bezel design, we build it from scratch in 18k gold or platinum to fit exactly.
Step cuts are some of the most beautiful diamonds to design around, and we love working with clients who are drawn to them. The quiet elegance of a perfectly chosen emerald or asscher cut, set well, is one of the most striking pieces of jewellery you will ever wear.
Book a Consultation
If you are considering a step-cut diamond engagement ring in Singapore, we would love to show you what is possible. Our showroom is at 176 Orchard Rd, #03-05 The Centrepoint, Singapore 238843. Consultations are by appointment and completely without obligation.