Asscher Cut Diamond
The Asscher is a square step cut with cropped corners and a deep, mirror-like "X" you see when you look straight down into it. Here is how it behaves, and why grade matters more here than on most shapes.
Key Takeaways
- An Asscher is a square step cut with cropped (cut) corners, giving it a near-octagonal outline and a 1:1 length-to-width ratio.
- Joseph Asscher designed and patented it in 1902 — the world's first patented diamond cut — and it became an Art Deco icon in the 1920s.
- Step cuts trade sparkle for clear, mirror-like flashes and a hypnotic concentric "X". That openness shows every inclusion and any body colour, so we recommend higher clarity (VS2 or better) and colour (G or better).
- Asscher and emerald are close cousins: both are step cuts, but the Asscher is square while the emerald is rectangular.
- GIA does not issue an overall cut grade for the Asscher — only round brilliants get one — so you judge it by eye, polish, symmetry, and ratio.
What is an Asscher cut diamond?
An Asscher cut is a square diamond cut in the step-cut style, with its four corners cropped off so the outline reads as a soft octagon. Instead of the many small triangular facets that make a round brilliant twinkle, a step cut uses long, flat facets arranged in parallel rows — like a set of stairs running toward the centre. Look straight down into a well-cut Asscher and those rows draw your eye into a deep, reflective "X" at the middle. People describe it as looking into a hall of mirrors. It is calm and architectural rather than fiery.
The cut carries real history. Joseph Asscher designed and patented it in 1902 through the family's Dutch firm, now the Royal Asscher Diamond Company, and it became the world's first patented diamond cut. It hit its stride in the 1920s, when Art Deco design loved anything geometric and symmetrical, which is why a lot of people still read an Asscher as "vintage" or "antique" even in a brand-new ring. The modern Royal Asscher version adds extra facet rows for more life, but the classic look is unmistakable.
Why higher grades matter on an Asscher
Step cuts are honest. The wide-open facets that make an Asscher so striking also act like a window straight into the stone, so anything inside or any tint shows plainly. A round brilliant can hide a small inclusion in its sparkle; an Asscher can't. The same goes for body colour, which pools in the corners and along the long facet lines.
That is why we steer customers toward better-than-average grades on this shape. For clarity, aim for VS2 or higher, and look at the actual stone or a clarity photo rather than trusting the letter grade alone — placement matters more than the count. For colour, G or better keeps the stone reading clean and icy, especially in white gold or platinum. If you love a warmer look or you're setting in yellow gold, you can relax the colour a touch, because the metal masks it. GIA's clarity and colour scales are explained on the GIA 4Cs site.
One more thing on grading: GIA assigns an overall cut grade only to round brilliant diamonds. Fancy shapes, the Asscher included, get polish and symmetry grades and a proportion diagram, but no single "cut" score — that is confirmed in GIA's own cut-grade explainer. So with an Asscher you lean on your own eye, the symmetry grade, and how square and centred that "X" looks.
Asscher vs emerald: the family resemblance
These two get mixed up constantly, and for good reason — they are both step cuts and they handle light the same way, in broad flat flashes rather than sparkle. The headline difference is shape. An Asscher is square (about 1:1). An emerald is rectangular and elongated, usually somewhere between 1.3:1 and 1.5:1. The Asscher's cropped corners are often more pronounced, which deepens that octagonal, layered feeling.
| Feature | Asscher | Emerald |
|---|---|---|
| Outline | Square, near-octagonal | Rectangular |
| Typical ratio | ~1:1 | ~1.3:1 to 1.5:1 |
| Light pattern | Deep concentric "X", windmill effect | Long parallel flashes, hall-of-mirrors |
| Cut style | Step cut | Step cut |
| Recommended clarity | VS2 or better | VS2 or better |
| Recommended colour | G or better | G or better |
| Finger look | Compact, geometric | Elongating, slimming |
So the choice is mostly about proportion and the feeling you want. The emerald lengthens the finger and reads sleek. The Asscher is squarer and more symmetrical, with a bolder pull toward the centre. Both want the same care on grade, because neither one hides anything. Both also benefit from a protective setting — those cropped corners are less fragile than a sharp point, but step cuts still earn their keep in bezels or with corner prongs.
Choosing and setting an Asscher
If you want the cut to look as square as possible, check the length-to-width ratio sits close to 1.00; even a small stretch is visible on this shape. A perfectly centred, symmetrical "X" is the sign of good cutting. Asschers pair beautifully with Art Deco-inspired settings, geometric halos, and clean solitaires that let the stone's lines do the talking. On our Coquitlam bench we often set Asschers in a four-prong basket that grips the cropped corners, or a full bezel when someone wants a low-profile, snag-free everyday ring.
If you're weighing it against other shapes, it helps to feel the contrast. The round brilliant is the opposite end of the spectrum — maximum fire and forgiveness. The oval and the cushion both lean softer and sparklier than a step cut. Seeing them side by side usually makes the decision obvious. For the full picture, start at the Diamond Shapes Guide, and when you're ready to design around your stone, our custom engagement ring guide walks through the rest.
Frequently Asked Questions
Is an Asscher cut diamond more or less sparkly than a round?
Less. The Asscher is a step cut, so it produces broad, mirror-like flashes and a striking concentric pattern rather than the small-scale fire and brilliance of a round brilliant. If you want maximum sparkle, a round or a brilliant-cut fancy shape suits you better; if you love a clean, glassy, geometric look, the Asscher is hard to beat.
What clarity and colour should I buy for an Asscher?
We recommend VS2 or higher clarity and G colour or better. Step cuts have large open facets that reveal inclusions and body tint that a round brilliant would hide. Always look at the stone or a clarity image to check where any inclusions sit, since placement matters more than the grade letter alone.
Asscher vs emerald — what's the actual difference?
Both are step cuts with the same light behaviour. The Asscher is square (roughly 1:1) with a deep central "X"; the emerald is rectangular and elongating (around 1.3:1 to 1.5:1) with long parallel flashes. Choose the Asscher for a compact, symmetrical look and the emerald to lengthen the finger.
Does GIA give an Asscher cut a cut grade?
No. GIA issues an overall cut grade only for round brilliant diamonds. For an Asscher, the report shows polish and symmetry grades, measurements, and a proportion diagram, so you judge the cut by eye, by the symmetry grade, and by how square and centred the pattern looks.
When was the Asscher cut invented?
Joseph Asscher designed and patented it in 1902 through the Dutch firm now known as the Royal Asscher Diamond Company. It was the world's first patented diamond cut and became one of the signature shapes of the Art Deco era in the 1920s.
Is an Asscher cut a good choice for everyday wear?
Yes. Its corners are cropped rather than sharply pointed, which makes them less prone to chipping than a pointed shape. We still recommend a protective setting — corner prongs or a bezel — for daily wear. Come by our Coquitlam studio and we can show you how different settings sit on the hand.