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The Asscher is a square step cut with deeply cropped corners — essentially a square emerald cut, with a hypnotic concentric 'windmill' when you look straight down. Vintage, architectural and quietly glamorous, it is the connoisseur's shape. Like the emerald, it rewards high clarity. Here is the guide.
Key takeaways
- An Asscher is a square step cut — the emerald's square sibling.
- It produces a mesmerising 'windmill' of concentric squares, not crushed-ice sparkle.
- Its open facets show inclusions and colour, so it rewards higher clarity and colour.
- The classic ratio is square, about 1.00–1.05.
- It has timeless art-deco glamour and suits clean, symmetrical settings.
What is an Asscher cut?
Created by the Asscher brothers in 1902, it is a step cut — long, parallel facets like stairs — in a square outline with cropped corners, giving an almost octagonal shape. Look straight into a well-cut Asscher and the step facets create a striking series of concentric squares, the famous windmill. It surged in the art-deco era and never lost its sophistication.
Why clarity and colour matter
Like its cousin the emerald cut, the Asscher's open, mirror-like facets reveal what is inside — so inclusions and body colour show more than in a sparkly brilliant. An eye-clean, high-colour stone is the right call, which is exactly where Montare's D–E, VVS1–VVS2 floor shines. See diamond clarity explained.
Every centre diamond is Triple Excellent, D–E, VVS and at least three carats — the hard calls are made for you.
Design your ringShape and ratio
An Asscher is defined by being square — a 1.00 to 1.05 ratio. Larger Asschers show the windmill best, and the cropped corners make it durable and comfortable. It looks a touch smaller per carat than a brilliant of the same weight, so it is a shape chosen for character, not size.
The best settings for an Asscher
Clean, symmetrical settings suit it best: a solitaire on a slim or knife-edge band, a halo for sparkle and size, or a three-stone with tapered baguettes for full deco effect. See our guide to settings and compare shapes in our visual guide.
Asschers and the Montare standard
The Asscher rewards precision and a high grade more than almost any shape — see why Triple Excellent matters. Every Montare Asscher is lab-grown, D–E colour, VVS1–VVS2 clarity, Triple Excellent, three carats minimum, IGI certified. Design one in the ring builder or book a consultation.
Design your ring in minutes. Every centre diamond is D–E colour, VVS clarity, Triple Excellent cut and at least three carats — IGI certified, made to order in Toronto.
Open the ring builder →Frequently asked questions
What is the difference between an Asscher and an emerald cut?
Both are step cuts, but the Asscher is square with a distinctive concentric 'windmill', while the emerald is rectangular with a long hall-of-mirrors look.
Do Asscher cut diamonds sparkle?
They produce broad, mirror-like flashes and a hypnotic windmill rather than fiery brilliance — elegant and understated, like the emerald cut.
Why does clarity matter for an Asscher?
Its open step facets reveal inclusions and colour, so an eye-clean, high-colour stone is best. Montare's VVS, D–E floor covers this.
What ratio is an Asscher cut?
Square — about 1.00 to 1.05.
See an Asscher to standard. Build one in the ring builder or book a consultation.
The Montare standard
Lab-grown · D–E colour · VVS clarity · Triple Excellent · 3ct minimum · IGI certified
Every ring is made to order in Toronto and backed by our lifetime setting upgrade, with free, fully insured shipping.
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