Asscher cut - how to choose the best cut?

[diamondseeker2006]

Yes, .3mm difference absolutely can be seen in stones this size. I'd go as close to 2 cts with the largest diameter if you want to add side stones. The picture in your avatar is of a center stone that is 3.95 cts. So it is going to be a much different look with a 1.5 ct stone. The sides would be tiny.

I like the stone tyty just posted, but I don't know if you are willing to go to H color. I would absolutely include G's, personally, as a well cut G is better than a lesser cut D-F.

I am still hoping you hear from the RA people, but I'd have to look back at the diameter on that one.

 

[Matthews1127]

Yes, .3mm difference absolutely can be seen in stones this size. I'd go as close to 2 cts with the largest diameter if you want to add side stones. The picture in your avatar is of a center stone that is 3.95 cts. So it is going to be a much different look with a 1.5 ct stone. The sides would be tiny.

I like the stone tyty just posted, but I don't know if you are willing to go to H color. I would absolutely include G's, personally, as a well cut G is better than a lesser cut D-F.

I am still hoping you hear from the RA people, but I'd have to look back at the diameter on that one.

The one tyty333 posted, meaning the 1.91ct?

 

[scarsmum]

Yes, .3mm difference absolutely can be seen in stones this size. I'd go as close to 2 cts with the largest diameter if you want to add side stones. The picture in your avatar is of a center stone that is 3.95 cts. So it is going to be a much different look with a 1.5 ct stone. The sides would be tiny.

I like the stone tyty just posted, but I don't know if you are willing to go to H color. I would absolutely include G's, personally, as a well cut G is better than a lesser cut D-F.

I am still hoping you hear from the RA people, but I'd have to look back at the diameter on that one.

Here’s a size comparison, I can’t see a difference
https://www.diamdb.com/compare/1.6ct-asscher-6.5x6.5x4.3-vs-1.8ct-asscher-6.56x6.56x4.4/

 

[asschercut]

They are both small and the real solution is to buy a 3-5ct, of course! (Pending a lottery win)

Nice detective work @tyty333, the 1.91 now looks much better than originally anticipated. That said, @diamondseeker2006 is right that H-color is too low for me. I agree that a well cut G can be better than a lesser D-F but the problem with online shopping is that it's so hard to assess cuts - Blue Nile will only provide ASETs after you buy, and I don't want to (and probably can't) keep buying and refunding, not to mention that I am not located domestically.

I still have not heard back from the eBay seller and may follow up soon, but the RA is just a 1.56ct so it would be smaller than any of the options we've currently discussed. And although my original parameters were between 1.49 and 2.01ct, I'm heeding your advice to go bigger, assuming that I can still stay within $15,000 USD.

 

[asschercut]

still think it windows when it's facing about 75degrees to the right and left, though

Would you mind providing a screenshot about what "windowing" means? I'm not sure I follow, and googling it brings up a bunch of window cleaning services

 

[asschercut]

What makes this 2.00ct D-VVS2 worth $42,000??? The symmetry is only VG, it's super deep, the corners are small, and the steps don't even turn on nicely. Surely it can't simply be due to the perfect color...

 

[Matthews1127]

What makes this 2.00ct D-VVS2 worth $42,000??? The symmetry is only VG, it's super deep, the corners are small, and the steps don't even turn on nicely. Surely it can't simply be due to the perfect color...

Good question. I’m hesitant due to the Cut grade: “ideal”. When did GIA start grading “cut” on step Cuts?

 

[asschercut]

Sounds like the retailer is just trying to inflate the stone's value!

 

[OoohShiny]

Would you mind providing a screenshot about what "windowing" means? I'm not sure I follow, and googling it brings up a bunch of window cleaning services

lol

This is a good example, although in coloured stones instead of diamonds:
https://www.pricescope.com/community/threads/windows-at-the-smithsonian-gem-exhibition.232418/

Basically it's where you can look through and see the thing on the other side / underneath of the stone, rather than reflected light from facets within the stone (which is the whole point of cutting diamonds - to reflect light back at you!).

It seems that some asschers seem to suffer 'tilt windowing' when the stone is tilted at an angle (which can be seen where the facets are the same colour as the background in the videos, if I am correct) but others are just fine - just one more thing to consider when shopping!

 

[asschercut]

At the same angle, it seems to me that all four (1.78, 1.90, 1.91, and 1.64) stones suffer from this windowing effect, though the 1.90 does it to a lesser effect. Good to know.

 

[foxinsox]

What makes this 2.00ct D-VVS2 worth $42,000??? The symmetry is only VG, it's super deep, the corners are small, and the steps don't even turn on nicely. Surely it can't simply be due to the perfect color...

It’ll be the top grade colour and the high clarity combined. Both attract a premium.
Outside of RB, the cut isn’t graded - this is part of why cut isn’t something consumers generally use when buying because it’s not neatly noted down alongside the other specs. As you’re discovering, it requires quite a lot of work to get a well cut stone it’s worth the effort tho since cut is the primary determinant of whether a diamond does its job right and sparkles.

 

[diamondseeker2006]

Here’s a size comparison, I can’t see a difference
https://www.diamdb.com/compare/1.6ct-asscher-6.5x6.5x4.3-vs-1.8ct-asscher-6.56x6.56x4.4/

In your comparison above, the stones are the same size... both 6.5mm. I am saying there will be a visible difference in a 6.5mm and a 6.8mm which is .3mm difference. (diamonds below made up just to show size difference..not referring to specific stones)

https://www.diamdb.com/compare/1.6ct-asscher-6.5x6.5x4.3-vs-1.8ct-asscher-6.8x6.8x4.4/

 

[diamondseeker2006]

What makes this 2.00ct D-VVS2 worth $42,000??? The symmetry is only VG, it's super deep, the corners are small, and the steps don't even turn on nicely. Surely it can't simply be due to the perfect color...

It's only worth that much if someone is crazy enough to pay for it!

 

[asschercut]

Just got ASET and Idealscope images for the 1.78ct. I don't really know how to assess the Idealscope but the ASET seems REALLY bad.

View media item 122456
View media item 122457

 

[diamondseeker2006]

Can you post them here? (It's after midnight here, so I won't see them until the morning, if you do.)

 

[kenny]

Royal Asscher cut has 14 more facets than generic Asscher cut. It has 74 instead of 58 facets. Hence better light performance.

More facets does not mean better light performance any more than does higher clarity or color grade.
More facets just means more, but smaller, facets ... which means more, but smaller, flashes of light.

The quality of light performance depends on facets being put in the right place and the right angles, not how many there are.

 

[asschercut]

I just realized that the attachments I uploaded last night are not publicly viewable.

Do these links work?

ASET: https://www.pricescope.com/community/attachments/gia-1186402112-aset-white-01-jpg.607624/ (Alternative link)

Idealscope: https://www.pricescope.com/community/attachments/gia-1186402112-idealscope-01-jpg.607625/ (Alternative link)

 

[scarsmum]

I wouldn’t call that a bad aset. Very even distribution, little light loss. https://www.prosumerdiamonds.com/is-red-better-than-green-in-an-aset/

 

[asschercut]

Very informative, thank you. I've been erroneously applying the ASET standard for rounds (e.g. red > green) to Asschers and I was also under the same impression when using this chart as a baseline reference. And I've since discovered this thread discussing the pros and cons for six different ASETs.

For this 1.78ct, it seems to me that it's very good at minimizing the white parts (windowing?) and the black parts (light obstruction), though maybe you'd still want some if you're looking for a sequential on-off pattern like I am.

 

[asschercut]

Is it just me or is this 1.65ct very peculiar?

It's got an excellent octagonal shape (probably the best I've seen yet), a tiny table of 56%, and great scintillation (though admittedly, not much going on at the north and south sides). But there's no GIA report and the symmetry is only graded as "good". Medium fluorescence is something to keep in mind.

 

[scarsmum]

Is it just me or is this 1.65ct very peculiar?

It's got an excellent octagonal shape (probably the best I've seen yet), a tiny table of 56%, and great scintillation (though admittedly, not much going on at the north and south sides). But there's no GIA report and the symmetry is only graded as "good". Medium fluorescence is something to keep in mind.

I thought no you may find that the culet is not centered, which will account for both the good and very good. However, I think it’s a rather beautiful stone.

 

[scarsmum]

Correcting to say both the “good”s. The lack of symmetry may, however, throw off the light return pretty substantially.

 

[OoohShiny]

That 1.65 is pretty interesting - I like the faceting and the fact it looks to perform well, even if not graded as excellent!

At the same angle, it seems to me that all four (1.78, 1.90, 1.91, and 1.64) stones suffer from this windowing effect, though the 1.90 does it to a lesser effect. Good to know.

I think @Karl_K would be best placed to comment on the technical aspects of windowing at tilt angles - I am a mere mortal and may well be wrong

I wouldn’t call that a bad aset. Very even distribution, little light loss. https://www.prosumerdiamonds.com/is-red-better-than-green-in-an-aset/

That's an interesting link, thanks for posting it

 

[Karl_K]

You rang :}
There are a few things I think I can say in general.
I can not comment on individual diamonds.
When you see color in a vendors video/photo that is impossible to be the diamonds body color it is either fire or something in the environment reflected in the diamond. Sometimes its even an interaction with the camera lens coating.
Many videos and pictures taken in commercial light boxes and over obstructed its like viewing the diamond at 3 inches wearing a face mask.
Some diamonds with beautiful contrast patterns have been dismissed as having "bow ties" because of the over obstruction.
Which brings us to patterns, remember what I have said for over a decade contrast patterns are what make step cuts unique and beautiful.
https://www.pricescope.com/journal/virtual-facets-and-patterns-discussion-about-step-cuts
https://www.pricescope.com/journal/performance-and-p3-facets-discussion-about-step-cut-diamonds
and:


Not everyone is going to like the same contrast patterns.


Now huge dark zones can be an issue and dark zones that do not flash or stay dark at to great a distance are also issues.

In my opinion with step cuts ASET is indicative not definitive for most things in step cuts.
I does provide a quick answer about the p3 facets.
I often go back and forth between video and ASET and look at all the different areas of the diamond from the center out.
I check the p3 facets first, then overall ratios of obstruction/leakage to bright areas in both video/pictures and ASET.
How the patterns flash with movement is vitally important to the quality and enjoyment of a step cut.
A step cut with a perfect ASET that does not dance is far worse than one with a somewhat flawed ASET image that dances like crazy.

 

[Karl_K]

I wouldn’t call that a bad aset. Very even distribution, little light loss. https://www.prosumerdiamonds.com/is-red-better-than-green-in-an-aset/

I dont have time to go into it but there are some serious errors on that page.
But it is true that green is not an evil demon lol

 

[OoohShiny]

Many thanks for your kind input, @Karl_K!

 

[asschercut]

I've now reviewed all available Asschers from Blue Nile, James Allen, White Flash, Good Old Gold, Brilliant Earth and Enchanted Diamonds, totaling just over 70 unique stones that had pictures/videos. Minimum specs: 1.60ct, F, VS2, and max budget of $15,000 USD.

There are only four that meet my cut standards, and in this exact order:

1. 1.78 F VVS2 (GIA) (ASET) (Idealscope) - some of you like this, some of you don't
2. 1.65 D VS2 (GIA) - seems like you all like this one, but the bad symmetry rating gives me doubts
3. 1.80 F VS2 (GIA)
4. 1.82 D VS1 (GIA)

Which of these would you buy? I don't have any options left if not these - I'm not in any rush to buy so I could wait for new stock to arrive, but Asschers are not particularly popular so who knows if there will be new stones anytime soon.

Also, that eBay seller with the 1.5ct Royal Asscher never responded, so they are eliminated from consideration.

 

[foxinsox]

Not any sort of asscher expert (I'm assuming you've checked the steps light up and step in and out when rotated etc) but I like the 1.65 D, then 1.80 F and 1.82 F (very close between these two) and finally the 1.78 F. I LOVE octagonal asschers with fat windmills so have chosen based off that.

 

[OoohShiny]

1.78 performs well but a bit of windowing at 70-80 degree tilt angles? Interesting facet patterns, with what looks like a mix of chunkier and slimmer facets as the stone moves. Contrast pattern is decent head-on. VVS2 should be completely eye-clean. F is a good 'colourless' colour - looks colourless but without the cost of an E or D.

1.65 performs well but a bit of windowing at 70-80 degree tilt angles? Chunkier contrast pattern that is attractive, but the inclusion looks to be visible in reflections in other facets under the table, which tweaks my mind-clean OCD lol. Good spread for the weight and a nicely lower cost due to the lower weight.

1.80 performs well but a bit of windowing at 70-80degree tilt angles? I like the contrast pattern head-on, though.

1.82 perform wells with minimal dead facets or windowing, but the table inclusion tweaks my mind-clean OCD


All IMHO, of course, and I am no expert!

 

[MarionC]

The 1.65 is the brightest to me and would be my choice if I did not mind the inclusion.

I know this one is over budget, but I include it here, just to look at. I dont know how to link it. I apologize in advance that it may not be pertinent, or
Maybe someone posted it and i didn't see.
At the end of the day, you can analyze cuts to death, but even with imperfections like windows, there will be a stone so beautiful that it doesn’t matter.
They have to be seen in person, so you do the best you can with your limited information and then see.

Ps. Looked at it again and really like the 1.65!