Step Cut Windowing: Emerald and Asscher Checks

By Josh Allen, Co-Founder of YourDiamondGuys.com. Fifth generation diamantaire with 30+ years in the global diamond trade. Former supplier to Tiffany & Co., Cartier, and Harry Winston.

Reject this fast, step cut windowing makes emerald and asscher diamonds look see through, and a good step cut should show clean flashes and structure.

Most buyers judge emerald and asscher cuts like they judge rounds. That is a mistake. Step cuts do not hide much, and their biggest problems show up fast once you know where to look.

I always start with GIA for natural diamonds. Not because the cut grade alone is enough, but because GIA gives me proportions I can actually trust. Softer lab reports do not give me the same confidence in those numbers.

Step cuts are honest. They show inclusions, body color, windowing, and extinction quickly. That is why I would rather reject a weak emerald cut early than defend it later.

What Windowing Means

Windowing is a see through area in the diamond. Instead of returning light, the stone lets you look through it.

In an emerald cut, windowing can show up through the center. In an asscher, it can weaken the hall of mirrors pattern.

Windowing vs Extinction

Windowing is too much see through. Extinction is too much darkness. Both can make a step cut underperform.

Clarity Matters More In Step Cuts

Emerald and asscher cuts are more transparent than brilliant cuts. Inclusions are easier to see.

I usually start at VS2 or cleaner for step cuts, then judge the exact inclusion. A VS2 with a white feather near the side is not the same as a dark crystal under the table.

The Slow Tilt Test

Tilt the stone slowly. You should see clean flashes turn on and off like mirrors. You should not see a dead glassy center.

A great step cut is quiet, not dull. That difference matters.

Reach out to Rob or me at YourDiamondGuys.com, or book your free consultation. We will look at the actual stone with you. No sales pitch.

Where Step Cuts Tell The Truth

Use this guide before approving emerald or asscher cuts. Step cuts are honest stones. They show body color, inclusions, windowing, and pattern weakness quickly. That is why I would rather reject a weak step cut early than try to explain away a dead center later.

Mistakes I Would Skip

1. Do not expect emerald and asscher cuts to sparkle like round brilliants.
2. Do not ignore a see through center.
3. Do not compromise too far on clarity in a transparent step cut.
4. Do not approve a step cut without seeing slow movement in video.

Emerald Cut Desk Example

A clean emerald cut can look quiet and expensive. A weak emerald cut can look like a piece of glass. The report does not always make that difference obvious. I would look through the center in video. If the background shows through too easily, that is windowing. If the stone goes black and never wakes up, that is extinction. A good step cut should give clean flashes that turn on and off as it moves. I also check the table area first because that is where buyers usually notice problems after the ring is on the hand.

Questions I Ask About Windowing

1. Can I see the stone tilt slowly in video?
2. Is there visible windowing through the center?
3. Where are the inclusions located under the table?
4. Does the diamond show clean hall of mirrors flashes?

Where I Would Compare Step Cut Videos

Use these sites as comparison tools, not automatic recommendations. For fancy shapes, I would compare actual stone videos on Brilliant Earth and Ritani, then judge the outline, bowtie, leakage, and spread for myself. The logo does not make the diamond better.

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Questions? Reach out directly for a free consultation, or drop them in the Diamond Buyers Academy community — Rob and I answer personally.