Step Cuts: Emerald, Asscher, Baguette and Carre
A brilliant hides a stone's faults behind sparkle. A step cut does the opposite: it opens a window straight down into the material and dares you to look. That honesty is why the trade respects them and why they are so much harder to buy well.
A step cut has no triangular facets. Its facets run in parallel bands around the stone, each one a little smaller than the last, like the terraces of a stepped roof. Light entering the table travels down and comes back in broad slabs rather than a scatter of points, which produces long flashes and a clear view into the interior.
Emerald cut
A rectangle with the corners cut off and three or more rows of steps on the crown and pavilion.
The name comes from the shape emeralds were traditionally cut in, and the reason is structural rather than aesthetic: emerald is brittle and the corners are where it chips, so cutting them off protects the stone. Applied to diamond from about 1920, the same outline became one of the defining shapes of Art Deco.
What to look at. The steps should be parallel and even; wandering step lines are the mark of a rushed cut. The corners should be equal. And because you are looking straight in, clarity matters more here than in almost any other shape.
Asscher cut
A square emerald cut with deeper corners, a higher crown and a smaller table, patented by Joseph Asscher in Amsterdam in 1902.
Period Asschers are Art Deco objects and they look it: tall, architectural, and with a distinct effect down the centre that dealers call the windmill or the hall of mirrors. The modern revival, sold from the early 2000s, is squarer, shallower and cut with extra facets for brightness. Both are legitimate; only one is antique, and the difference shows in the crown height from the side.
Baguette
A long thin step cut with two or three steps, named for the loaf.
The baguette arrives in the 1920s and it is the reason Art Deco looks the way it does. Round stones cannot draw a straight line; baguettes can. Set in rows they make the bars, chevrons and stepped outlines the period is built from. A tapered baguette, wider at one end, lets a line curve gently without breaking.
Carre cut
A true square with uncut corners.
Carre stones are the ones set edge to edge in channels with no metal showing between them. That fit is not luck: each stone was cut to its own space in the mount, which is what calibre cutting means and what makes a good Deco piece expensive to make and expensive to repair. If you see metal visible between the squares in a supposedly period piece, the stones were bought to size and the piece is almost certainly later.
Table cut, the ancestor
Every step cut descends from the table cut: a natural diamond crystal with its point ground flat, in use from about 1400.
How to tell period from revival
| Period, 1900 to 1940 | Modern revival | |
|---|---|---|
| Crown height | Tall, noticeably above the setting | Shallow, flush |
| Table | Small | Wide |
| Corners on an Asscher | Deep, giving an almost octagonal look | Shallower, squarer |
| Culet | Often small but open | Closed |
| Setting | Platinum, millegrain worked with a wheel | White gold, millegrain cast |
| Neighbouring stones | Calibre cut to fit, no metal between | Standard sizes, metal visible |
The stone and the setting must agree. A tall-crowned Asscher in a cast white gold mount is a period stone that has been reset, which is fine and worth knowing. A shallow modern Asscher in a supposedly 1925 platinum mount means either the stone or the mount is not what it is being called.
Living with them
Step cuts chip at the corners, which is precisely why emerald cutting exists. Any step-cut stone should sit in a setting that covers its corners, and a piece where the corners are exposed should be treated as fragile regardless of what it is made of.
They also show dirt more than brilliants do, because you are looking straight through them. A soft brush and warm water is enough for a modern piece; for anything antique, and certainly for anything with a closed back, read the cautions in inherited jewelry before putting it near water.
Frequently asked questions
What is a step cut?
A cut whose facets run in parallel bands around the stone rather than in the triangular and kite shapes of a brilliant. Emerald, Asscher, baguette and carre cuts are all step cuts.
Why do emerald cut diamonds sparkle less?
Because they are not designed to. Step cuts return light in broad flashes rather than scattering it into many small points. What they give instead is depth and a clear view into the stone.
Do step cuts show inclusions more?
Yes, considerably. With no scintillation to break up the view, an inclusion that would vanish in a brilliant is plainly visible in an emerald cut. Buy a step cut a clarity grade or two higher than you would otherwise accept, or better, buy the one that looks right to you.
What is the difference between an Asscher cut and an emerald cut?
An Asscher is square with deeper cut corners, a higher crown and a smaller table. An emerald cut is rectangular with shallower corners. Period Asschers date from 1902 onward and are noticeably taller than the modern revival.
Are baguettes real diamonds?
Yes. A baguette is a shape, not a material or a quality. They are small and usually accent stones, which is why they are cheap per stone, but they are cut from the same rough as anything else.
What does calibre cut mean?
Stones cut individually to fit an exact space in a setting so they sit edge to edge with no metal between them. It is slow, expensive work and one of the clearest signs of a good Art Deco piece.