Its character
Square in outline, with corners cut back far enough that the stone reads as an octagon and the steps draw the eye straight down to the culet. Like the emerald cut it hides nothing, so clarity is graded strictly. Higher crowns and smaller tables distinguish it from a square emerald.
Where the asscher cut comes from
The asscher cut was created in 1902 by Joseph Asscher of the Asscher family firm in Amsterdam, the same firm that later split the Cullinan diamond. It was widely used in Art Deco jewellery and then became less common until a revival around 2000.
Laboratory reports often describe an asscher as a 'square emerald cut', since the two share the same step-cut structure.
How a asscher is faceted
A classic asscher has around 58 step facets, with a square outline, deeply cropped corners, a high crown and a relatively small table. Seen from above, the corners make the outline look almost octagonal.
When the proportions are right, the steps create a windmill or X-shaped pattern that draws the eye toward the centre of the stone. Like the emerald cut, it shows inclusions and colour clearly.
Asscher cut proportions
Ranges most well-cut asscher stones fall within. They narrow the field; they do not replace seeing the stone.
| Measure | Typical range | Why it matters |
|---|---|---|
| Table | 60 – 68% | Smaller tables are closer to the original design. |
| Depth | 60 – 70% | |
| Length to width | 1.00 – 1.05 | Longer stones read as a square emerald cut. |
| Girdle | Thin to slightly thick | |
| Culet | None to small | |
| Cut grade | Not graded | Neither GIA nor IGI assigns an overall cut grade to this shape, so these are trade ranges rather than a standard. |
What to look for in a asscher diamond
Look for the windmill — four clean arms running in from the corners — which only appears when the proportions are right. An outline between 1.00 and 1.05 is expected; anything longer is closer to a square emerald cut. As with the emerald, the plot on the report matters more than usual, because the open facets show everything inside.
- The windmill
- Look for four clear arms running from the corners toward the centre. If they are missing or uneven, the proportions are likely off. It is judged by eye, not graded.
- Squareness
- Check that the ratio is close to 1.00 and that all four cropped corners are the same size.
- Clarity and colour
- As with the emerald cut, the open facets show inclusions and body colour. Read the plot and consider higher grades than for a brilliant.
- Crown height
- A very flat crown weakens the step pattern. The profile view in a video helps judge it.
Setting a asscher
Four prongs at the cropped corners are standard, and asschers suit vintage, Art Deco and halo designs. They pair well with baguettes and other step cuts.
Asscher size by carat weight
Approximate face-up size at a typical asscher ratio and depth, drawn to scale. Select a weight to see natural stock in that band.
5 mm. Every silhouette is drawn to this scale, at typical proportions.
- Natural asscher diamonds, 0.25–0.49 ct, about 3.6 mm face up
- Natural asscher diamonds, 0.50–0.74 ct, about 4.6 mm face up
- Natural asscher diamonds, 0.75–0.99 ct, about 5.2 mm face up
- Natural asscher diamonds, 1.00–1.49 ct, about 5.7 mm face up
- Natural asscher diamonds, 1.50–1.99 ct, about 6.6 mm face up
- Natural asscher diamonds, 2.00–2.99 ct, about 7.2 mm face up
- Natural asscher diamonds, 3.00 ct and above, about 8.3 mm face up
Diamond carat guide: every shape, price milestones and choosing a weight
Terms used on this page
Each one is defined in full, with what a report prints for it, in the glossary.
- Step cut
- A faceting style of long parallel facets running around the stone like steps.
- Plot
- The diagram on a report marking where each clarity characteristic sits in the stone.
- Length-to-width ratio
- The outline's proportions — length divided by width — which decides how a fancy shape reads.
- Crown
- Everything above the girdle: the sloping top of the stone.
- Table %
- The width of the table facet as a percentage of the stone's average diameter.
- Eye-clean
- No inclusion visible to an unaided eye at normal viewing distance.
Asscher cut questions
What buyers ask most often before choosing a asscher diamond.
What is the difference between an asscher cut and an emerald cut?
Both are step cuts with cropped corners. An asscher is square with larger cropped corners and usually a higher crown; an emerald cut is rectangular.
What clarity should an asscher cut diamond be?
Because step facets show inclusions easily, VS2 or higher is a common choice. Always review the plot, as the location of an inclusion matters more here than on a brilliant.
Why does a laboratory report call my asscher a square emerald cut?
Laboratories often use 'square emerald cut' as the shape description for asscher-style stones, since the facet structure is the same. The name asscher refers to the style first cut by the Asscher family.