Asscher Cut Diamonds

The Asscher is the choice of people who find brilliant cuts a little busy. It is the most architectural diamond shape there is, and the one most closely tied to a single design era.

It belongs to the step cut family rather than the brilliant family, a distinction the International Gem Society explains in detail. Step cuts use long parallel facets arranged like staircases instead of the many small triangular facets that produce fire in a round brilliant.

An Asscher is a square step cut whose four corners are cut away so deeply that the outline is really an octagon. Those cropped corners are the signature, and they are also what makes the shape so robust: there is no point anywhere on the stone that can catch and chip.

Three proportions define it. The crown is tall, the table is small, and the pavilion is deep. Together they force light to travel a long way inside the stone before it returns, which is what creates the stacked, receding square reflections you see when you look straight down into it.

The classic Asscher has 58 facets. A modern variant introduced in 1999 by the same family firm, the Royal Asscher cut, uses 74 and adds a second tier of facets for extra brightness. Both read unmistakably as Asschers.

The Asscher is one of very few diamond shapes with a named inventor and a date. Joseph Asscher designed it in Amsterdam in 1902 for the family firm, and it was the first diamond cut ever granted a patent. The same house was later entrusted with cleaving the Cullinan, the largest gem diamond ever found.

Its moment came with Art Deco. The geometry of the 1920s and 1930s, all symmetry and clean line and stepped form, suited the Asscher exactly, and it became one of the defining shapes of the period. When that patent lapsed and fashion moved on, the cut nearly disappeared for half a century.

It returned in the early 2000s alongside the wider revival of antique and vintage styles, and it remains a deliberate, slightly contrarian choice rather than a default one. Our vintage lab grown diamond engagement rings include an Art Deco style asscher pave ring.

Large open facets and a small table mean an Asscher behaves like a window. A brilliant cut scatters light fast enough to break up a small inclusion; a step cut simply shows it to you, magnified by the mirrored planes around it.

This is the single most important rule for the shape. Ronora works on a strict VVS-VS clarity ladder, VVS1 first, VVS2 next, and VS1 only when neither can be sourced, which is exactly the range an Asscher needs.

The same open geometry that reveals inclusions reveals tint. A warmth you would never notice in a round brilliant becomes visible across an Asscher's broad flat facets, especially near the cropped corners where the stone is deepest.

Every Ronora Asscher sits in the D-E-F colourless range, so the hall of mirrors stays clean and white all the way down.

A true Asscher is square. A length to width ratio of 1.00 to 1.05 looks square to the eye; past about 1.10 it starts to read as a small emerald cut instead, which is a different shape with a different character.

Look for the windmill too, the X of reflections radiating from the centre toward the four corners. A crisp, symmetrical windmill is the sign of a well-proportioned Asscher, and a faint or lopsided one means the depth or symmetry is off.

The deep pavilion that makes an Asscher beautiful also hides weight below the girdle. A 1.5ct Asscher will typically look smaller from above than a 1.5ct oval or marquise, which spread their weight outward instead.

Plan for it rather than being surprised by it: compare millimetre measurements, not carat weight, and consider stepping up a size if face-up presence matters to you. Our diamond measurements guide puts every shape side by side at the same weight. There is no cut grade for fancy shapes, so symmetry and proportion are what you judge instead.

See an Asscher cut at actual size on your own ring size, or as a stud or pendant, with Find Me Diamond, our free diamond size visualizer.

Nothing on an Asscher is fragile, so the setting is chosen entirely for character. The shape has a strong point of view, and the best settings agree with it rather than argue.

• Solitaire, four prong, thin band. Prongs sit on the cropped corners where they interrupt the least. The purest way to show the hall of mirrors. See solitaire rings.
• Three stone with trapezoids or baguettes. The definitive Art Deco arrangement. Straight-edged side stones extend the stepped geometry outward.
• Bezel. A full bezel traces the octagon and gives a modern, almost industrial result. Very durable, very clean.
• Art Deco detailing. Milgrain, filigree galleries, geometric under-galleries. This is the shape those techniques were designed around.
• Halo. A square or octagonal halo adds visible size without softening the outline. A round halo fights the shape, so keep it geometric, or use a hidden halo to leave the silhouette untouched.
• East-west. Less common on a square stone than on a long one, but a slightly elongated Asscher turned sideways makes an unusually good low-profile ring.

What it does well

• The hall of mirrors effect is unlike anything a brilliant cut can produce.
• Cropped corners mean nothing can chip. Among the most durable shapes to wear daily.
• Perfectly symmetrical, which suits three stone and Art Deco settings.
• Genuine design history, with a named inventor and the first diamond cut patent.
• Uncommon enough that it never looks like everyone else's ring.

What to watch

• Clarity is unforgiving. This is a shape where the VVS-VS ladder earns its keep.
• Colour shows more than on any brilliant cut.
• Faces up smaller than its carat weight suggests.
• No cut grade exists for fancy shapes, so proportion and symmetry must be judged directly.
• Ratios past about 1.10 stop looking like an Asscher.