Quantifying Performance Nuances beyond ASET, H&A Photos, etc

[diagem]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

pfunk said... If I can buy an ideal stone of 7.9mm diameter for the same price as a 7.5mm superideal, which do I buy? Is the effect of size more noticeable than symmetry?

The thing you are not taking into account is that size is not everyone's number one priority. I just bought superideal cut diamonds for earrings (upgrade policy) and I certainly could have gotten bigger stones had I gone with virtual inventory GIA EX. Same with my e-ring diamond which is a specialty cut. I could easily have gotten a GIA EX 3 ct mrb instead by dropping a little in clarity, too, but I didn't want a 3 ct diamond. Sometimes people choose quality over quantity. Bigger is not better to everyone. I remember a guy coming here one time with a $20k budget and he wanted a 1 ct D VVS-IF diamond. That is certainly not for everyone, but it is what his girlfriend wanted. Different people have different preferences.

Good points DS, which also compliment exactly what pfunk is trying to address.

Everyone who comes here seeking advice does so with their own set of priorities, or a general idea of what they seek to achieve. The forum provides the insight and shares the knowledge required to assist them in achieving their goals. Educating consumers about diamonds is something that the people here do, and do to a very high level.

However, all too often you see someone come with a limited understanding, not sure what they really want.. and from what I have seen they are almost always pushed towards super ideals. That by buying any less they are ultimately giving up something... something that can be qualified (selectively using ASET/IS), but not quantitivly at this stage in time. They are then faced with an option to either extend their budget, drop colours/clarity, or buy a smaller diamond.

I haven't been here long, but I have seen it unfold time and time again. On the other hand, if someone does come with a set of priorities or a particular goal I have also witnessed many of the regulars work towards that, even if it doesn't align with their own opinions/tastes.

I personally would be happy with some of WFs expert selection. I appreciate the symmetry, but don't need the perfect ASET/IS. Some leakage adds some character, as do inclusions to some people, as others like warmer coloured stones. Its all about what works for you... but for someone who doesn't particularly fuss over their stone, who isn't interested in gazing deeply at it at all hours, who doesn't desire to own a loupe, ah&a viewer, a mircroscope.. are they actually going to be aware of the small (unmeasurable) amount of performance they are giving up.

You are right of course, PS is the place if someone is looking for high[est] level education. For pros as for consumers.
We try to tell the ongoing story where the laboratories stop for various reasons which non are innovation - advancement.
The beauty of this place is simply for the fact that we share this information.
You can do with it as you like.
The fact that products already exist that AGSL does not recognize as above their top range is just a fact, we will need to overcome such obstacles. Give us some time as we justify our advancement claims. It's not such an easy task but well worth it I believe. After all Diamond material is the most valuable substance on earth. It certainly deserves such high detailing crafted by human hands. Some definitely appreciate the efforts, I thank and salute those who do.
I disagree with everyone who claims optical precision is not quantifiable at this stage and time, it's true, we can't put numbers on them yet but we can definitely visualize any differences in ETAS. (Virtual ETAS is problematic as it depends on 3D scans which include limitation errors!). But real ETAS is the most sensitive tool available. We have been researching real ETAS for over a year now. It's complicated but even slight out of 3D symmetry will be noticed and recognized. Real ETAS conclusions can give us a good direction of LP potential. (You can see an old visual of a real ETAS in my avatar.)

This thread is focused towards round brilliants but if you take fancy shapes into account optical precision becomes more complicated and interesting.

We are still in the diaper stages of optical design as far as Diamonds are concern.
I do wish AGSL would be a bit more welcoming to optical designs outside of their ray tracing "box" which was originally designed for round brilliants.

 

[John P]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

Some CBI-specific questions have been asked. While much of the following is specific to our channel, I do want to reiterate my respect for alternate opinions and choices.

Great write up, and I love these technical discussions. One thing regarding the HOF though. You could easily also attribute their success to being involved with savvy marketting and brand naming. Its seen all too often that people spend the most under the impression that due to it costing more, it must be better.

HOF does have an intimidating marketing budget. But so do the zillions of “H&A” brands which come-and-go in chain-stores. They go because HOF has visual teeth and they do not. HOF is also offered in reputable stores which are frequently AGS members and highly-regarded in their communities. Kobi, with respect, inferring that all those pros are actually pulling the wool over their clients’ eyes seems disingenuous, as does inferring that every HOF owner was lulled by a false siren-song of marketing (forgive me if that’s not your inference). CBI now works with several former HOF dealers. I find them to be standup people who want the best for their clients.

I truly find it fascinating how many people and how much development has been (and is being) employeed in this industry. One thing is for sure, public education will only see that this continues, which benefits all involved.

That’s music to my ears. We made a conscious decision not to inflate costs with marketing. Instead our focus is dealer-support and intensive education, trusting that a rising tide will lift all boats. We encourage our dealers to show people all options, and let clients make a fully informed decision that fits their individual situation.

To that end, read on. It’s like pfunk has been inside my head. In fact, to a degree, several posters have been…

I would ask the same about your showroom customers. I assume you only carry your CBI superideal stones, and with no "inferior" stones to serve as comparison…

That assumption would be wrong. All of our showroom dealers carry other diamonds, up to and including generic EX and Ideal. In fact, their gemologists sometimes request my help on cut-quality when calling-in competing diamonds (That might sound weird but those who know me personally won’t be surprised).

…certainly your customers will find your stones beautiful and are proud to purchase and own them. But if we took that stone and the customer who loves it, even after owning it for some time, and placed it in a lineup of generic AGS 000 stones of similar attributes other than cut, what percentage of customers would you think could pick their stone from the lineup?

I’d say many or most, but this is not CBI-centric. You invoked “the customer who loves it.” Read Karl_K’s reference to 2 weeks plus, in his prior post. Now extend that by months or years. In my experience true enthusiasts can pick their own beloved diamond out of any lineup, CBI or not.

Now let's take customers who are in the search for a diamond for their engagement. If you were to offer up a stone for each customer based upon what they are looking for and their budget, and then have them compare them to non h&a ideal stones, how often would the customer choose the CBI stone? If the other stones were allowed to be higher color/clarity/carat or a combination of them to match to the price of the CBI stone, would they still choose the CBI because the visual differences from the cut are profound enough to make them sacrifice on the other aspects? Obviously you probably don't know the answers to these questions, but they are certainly fair to bring up for discussion and debate would you agree?

Actually I do have answers. As a former teacher I’m constantly doing PDSA with our dealers. My study component from March was inspired by a discussion several of us had on this very forum; this thread specifically: [URL='https://www.pricescope.com/community/threads/show-me-examples-of-good-numbers-poor-idealscope.210997/page-3#post-3840276#p3840276']https://www.pricescope.com/community/threads/show-me-examples-of-good-numbers-poor-idealscope.210997/page-3#post-3840276#p3840276[/URL]

Survey Questions:

* When Showing diamonds, in general, next to Crafted By Infinity do your clients see a difference?
* If any do, how do they characterize the difference?
* If they purchase the CBI vs the general diamond what's the most commonly expressed reason?

* When showing a GIA3EX, top ASET, next to Crafted By Infinity do your clients see a difference?
* If any do, how do they characterize the difference?
* If they purchase the CBI vs the 3EX top ASET what's the most commonly expressed reason?

* Do any other reasons stand out?
* Generally speaking, which drives Crafted By Infinity purchases: 1 highest, 6 lowest.

So far 12 professionals in a few different CBI showrooms have submitted it (work in progress). Since they are at the counter every day, working with all kinds of diamonds and clients, their voices will be more meaningful than mine. I’ll need approval to share that internal info here. Stay tuned.

My regular showroom visits are the reason I keep saying: Many decisively see and want our specific look. Others see it but have a different priority. Others may say “meh,” or don’t see it at all. Vive la difference.

Tapping the brakes.

I have been on Pricescope a long time. I am 100% certain that this is the most detail I’ve ever been asked to disclose about the CBI brand. It’s rare that I even talk about it here... Pfunk, I thank you for inviting the questions. I see you have more and will try to answer to them, as well.

Stepping back, my foremost interest since leaving full-time education has been empowering confident diamond buying on the internet, and supporting great service by local jewelers. For the record, dozens of former students have approached me for engagement diamond advice. What I do is give them top-to-bottom information, point them to proper sources to experience everything and let them decide. Whether someone chooses a tiny EGL lopsy fugs, a 2ct D FL Tiffany, a rich antique cut, a pear, an Octavia or something completely different doesn’t matter, as long as they do it with eyes wide open.

 

[cflutist]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

Thank you John for your informative post. I always enjoy reading words coming from Sir John.

 

[teobdl]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

Thank you, Yoram, for bringing ETAS into the discussion. I have been thinking that it is presently the most effective way to understand and characterize diamond reflections to observers.

For those unfamiliar, the Cut Study group has a nice write up of what ETAS is here: http://www.cutstudy.com/cut/english/conference_posters/4.htm
With more visuals here:
http://www.cutstudy.com/cut/english/conference_posters/5.htm

ETAS is potentially much more helpful even to buyers because it would help them to see how differences in cut change the frequency and quality of reflections from all viewing angles and distances.

What are the limiting factors in making ETAS more widely available? Can one simply use a sarin scan to make an ETAS with the right software?

EDIT: Also, how significantly do the limitation errors of scans change the results of virtual ETAS? In other words, what aspects of a real ETAS is missed/mischaracterized in a virtual ETAS?

 

[pfunk]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

Some CBI-specific questions have been asked. While much of the following is specific to our channel, I do want to reiterate my respect for alternate opinions and choices.

Great write up, and I love these technical discussions. One thing regarding the HOF though. You could easily also attribute their success to being involved with savvy marketting and brand naming. Its seen all too often that people spend the most under the impression that due to it costing more, it must be better.

HOF does have an intimidating marketing budget. But so do the zillions of “H&A” brands which come-and-go in chain-stores. They go because HOF has visual teeth and they do not. HOF is also offered in reputable stores which are frequently AGS members and highly-regarded in their communities. Kobi, with respect, inferring that all those pros are actually pulling the wool over their clients’ eyes seems disingenuous, as does inferring that every HOF owner was lulled by a false siren-song of marketing (forgive me if that’s not your inference). CBI now works with several former HOF dealers. I find them to be standup people who want the best for their clients.

I truly find it fascinating how many people and how much development has been (and is being) employeed in this industry. One thing is for sure, public education will only see that this continues, which benefits all involved.

That’s music to my ears. We made a conscious decision not to inflate costs with marketing. Instead our focus is dealer-support and intensive education, trusting that a rising tide will lift all boats. We encourage our dealers to show people all options, and let clients make a fully informed decision that fits their individual situation.

To that end, read on. It’s like pfunk has been inside my head. In fact, to a degree, several posters have been…

I would ask the same about your showroom customers. I assume you only carry your CBI superideal stones, and with no "inferior" stones to serve as comparison…

That assumption would be wrong. All of our showroom dealers carry other diamonds, up to and including generic EX and Ideal. In fact, their gemologists sometimes request my help on cut-quality when calling-in competing diamonds (That might sound weird but those who know me personally won’t be surprised).

…certainly your customers will find your stones beautiful and are proud to purchase and own them. But if we took that stone and the customer who loves it, even after owning it for some time, and placed it in a lineup of generic AGS 000 stones of similar attributes other than cut, what percentage of customers would you think could pick their stone from the lineup?

I’d say many or most, but this is not CBI-centric. You invoked “the customer who loves it.” Read Karl_K’s reference to 2 weeks plus, in his prior post. Now extend that by months or years. In my experience true enthusiasts can pick their own beloved diamond out of any lineup, CBI or not.

Now let's take customers who are in the search for a diamond for their engagement. If you were to offer up a stone for each customer based upon what they are looking for and their budget, and then have them compare them to non h&a ideal stones, how often would the customer choose the CBI stone? If the other stones were allowed to be higher color/clarity/carat or a combination of them to match to the price of the CBI stone, would they still choose the CBI because the visual differences from the cut are profound enough to make them sacrifice on the other aspects? Obviously you probably don't know the answers to these questions, but they are certainly fair to bring up for discussion and debate would you agree?

Actually I do have answers. As a former teacher I’m constantly doing PDSA with our dealers. My study component from March was inspired by a discussion several of us had on this very forum; this thread specifically: [URL='https://www.pricescope.com/community/threads/show-me-examples-of-good-numbers-poor-idealscope.210997/page-3#post-3840276#p3840276']https://www.pricescope.com/community/threads/show-me-examples-of-good-numbers-poor-idealscope.210997/page-3#post-3840276#p3840276[/URL]

Survey Questions:

* When Showing diamonds, in general, next to Crafted By Infinity do your clients see a difference?
* If any do, how do they characterize the difference?
* If they purchase the CBI vs the general diamond what's the most commonly expressed reason?

* When showing a GIA3EX, top ASET, next to Crafted By Infinity do your clients see a difference?
* If any do, how do they characterize the difference?
* If they purchase the CBI vs the 3EX top ASET what's the most commonly expressed reason?

* Do any other reasons stand out?
* Generally speaking, which drives Crafted By Infinity purchases: 1 highest, 6 lowest.

So far 12 professionals in a few different CBI showrooms have submitted it (work in progress). Since they are at the counter every day, working with all kinds of diamonds and clients, their voices will be more meaningful than mine. I’ll need approval to share that internal info here. Stay tuned.

My regular showroom visits are the reason I keep saying: Many decisively see and want our specific look. Others see it but have a different priority. Others may say “meh,” or don’t see it at all. Vive la difference.

Tapping the brakes.

I have been on Pricescope a long time. I am 100% certain that this is the most detail I’ve ever been asked to disclose about the CBI brand. It’s rare that I even talk about it here... Pfunk, I thank you for inviting the questions. I see you have more and will try to answer to them, as well.

Stepping back, my foremost interest since leaving full-time education has been empowering confident diamond buying on the internet, and supporting great service by local jewelers. For the record, dozens of former students have approached me for engagement diamond advice. What I do is give them top-to-bottom information, point them to proper sources to experience everything and let them decide. Whether someone chooses a tiny EGL lopsy fugs, a 2ct D FL Tiffany, a rich antique cut, a pear, an Octavia or something completely different doesn’t matter, as long as they do it with eyes wide open.

John
Many, many thanks to you for your input here. As you can see, I am an inquisitive person (as so many here are). I seldom feel pleased by simply scratching the surface. I am here because I have taken a large amount of interest in diamonds, namely round brilliants as I have been reading here for months about them to make a more informed purchase. I genuinely like to help people, and do want to make sure my advice is as sound as possible.

I know many folks here likely see me as being anti-superideal. It's not the case at all, and I have nothing but respect for the vendors specializing in such stones and advancing consumer awareness on cut. I do hope that you, Paul, Wink, Jon, and Bryan can recognize that and view me not as a consumer set on turning people away from precision cut stones. If someone is interested in a superideal and has done their due diligence to come to that decision after weighing the pros and cons of each route, I am glad to recommend any one of you as you have earned the trust of so many and deserve every bit of business coming your way. I simply try to weigh in if it seems the person is not yet fully aware of the differences they can expect from a strictly visual standpoint.

I certainly wish to maintain mutual respect for one another, because as soon as that is lost the discussion becomes infinitely less useful for everyone. I am giving the opinions of an average consumer, admittedly a novice, which I hope you can see. Those opinions can be used as learning tools for you, just as I can learn from your expert opinions. I very much look forward to your added input here and thank you for taking the time to help me and others.

 

[teobdl]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

Great survey, John. It would be great if you could share some results, though I imagine it's valuable IP.

Also, I never did check back with the last thread you linked in which you responded to my posts. I think you articulated very well the macro evolution of cut improvements that have led to better looking and better reflecting diamonds. Thank you.

 

[Rhino]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

Great thread and great post John.

If I may add my .02c as this is a subject I've been studying over the past 15 years and even cutting diamonds to produce certain specific scintillation patterns. I always find this topic fascinating. Although addressed to John, if I may address some of your questions pfunk...

John,

First of all thanks so much for joining the fray here. I was very much hoping you might add your opinions. You addressed a couple of my quotes from the CBI website, but the others I will repost again in the case that you missed them on the other thread.

First statement: "Factually no laboratory has yet subdivided cut-quality components to anywhere near the level that color or clarity are subdivided. Doing this is already possible behind industry doors, but pressure from mass-manufacturers prevents public disclosure of greater cut detail for any given diamond."

True. It is one reason why we may never possibly see a formal grading for Optical Symmetry. The only lab I see possibly doing it would be AGS as they are already in a category by themselves grading light performance/leakage. Why not take it to the next level and do 3d symmetry grading? A good reason is it will isolate many manufacturers as very few are cutting precision goods.

Second statement: "One needs to look no farther than the youngest and largest-growing market (China) to find laboratories disclosing more cut value-factors and consumers who are more cut-educated than their USA counterparts. Diamond shoppers in this new market are not only more aware of cut-quality subdivisions; they also recognize the added value commanded by diamonds with non-accidental, extremely high levels of three-dimensional cut-precision. Sightholders and cutting houses serving this market have improved systems to satisfy growing eastern demand for fine-make. Eventually these modern value-factors will become recognized in the older USA market, but mass-manufacturers and retailers are in no rush to assist that recognition, due to the extra work, training time and expense it will require:"

Regarding statement number one: Is there information that you and other members of the trade are aware of that would further classify cut beyond what we are already seeing on lab reports? If so, are you and other superideal vendors trying to convince laboratories in the United States to include such information. I would think that a lab such as AGS, who specializes in cut, would be eager to bring such information forward as they already predominantly deal with vendors who focus on very well cut diamonds. Wouldn't this stand to improve their business even further as consumers would be more likely to purchase superideal stones and the demand for the laboratory service would increase?

You'd think so. Labs like AGS have to weigh the pros and cons of this. After all they are also a business and with an 11 grade cut grading system there are many diamond manufacturers who do not and will not submit their diamonds to AGS because of how strict they are on cut. If they make it even stricter they may be isolating themselves further. Personally I would love to see them grade for Optical/3D symmetry but you know what ... this to me is where true salesmanship comes to play. After all a lab report can only take you so far down the rabbit hole. Granted an AGS Report takes a consumer to a certain level down that rabbit hole but there are still plenty of things that are not included on that AGS Report. This is where a good knowledgeable salesman can step up and earn their keep. There will of course always be those majority of jewelry stores that are content selling simple GIA XXX at the cheapest prices they can find but gemologists who have both the education and the tools to demonstrate the differences between the best and worse GIA Ex's or AGS Ideals tap into the market of consumers who are being educated to these things and helping others to better understand what constitutes the value differences and allowing consumers to decide if that is a feature they want to pay for or not.

Regarding statement two: what additional cut information are these Chinese markets getting from these laboratories? And how is that information convincing the consumers there that there is added value for the superideal, prescision cut diamond? Meaning, are they quantifying more aspects of cut than US labs which acts to objectively prove to consumers the added value?

I'm just catching up in this thread but am curious to see what they are offering too.

As far as Hearts on Fire, the point that Kobi makes is an important one in my opinion. Great marketing can do wonders in the area of convincing consumers of things that may not be as obvious as it is made out to be. Additionally, when folks go in to buy a HOF diamond, what kind of stones do you suppose they are comparing the HOF stone to? AGS 000? Zenith of GIA excellent? I highly, highly doubt it. It's the same thing you see with online marketing of superideals. A picture of the perfect h&a next to the GIA excellent that doesn't even really have arrows and the ASET that looks like a kaleidoscope. No one who seeks help on PS would ever be recommended that type of stone, but yet they hear the constant degrading of the GIA excellent cut grade and honestly assume that's what they will end up with if they stray from a superideal stone.

As big as PS is, it is still just a microcosm in the world of diamonds. The grand majority of GIA XXX diamonds do not fall within what many of us would consider orthodox ideal proportions. (ie. 34-35 cr <, 40.6-41 pavilion <, 53-57 tables, depths =<62.2 etc.) not to mention the level of precision it takes for H&A symmetry. I keep one or two of these common GIA XXX's around as it pertains more to my local market than it does here on PS but yes ... the majority of consumers who are purchasing are in fact looking at these common GIA X's.

I would ask the same about your showroom customers. I assume you only carry your CBI superideal stones, and with no "inferior" stones to serve as comparison, certainly your customers will find your stones beautiful and are proud to purchase and own them. But if we took that stone and the customer who loves it, even after owning it for some time, and placed it in a lineup of generic AGS 000 stones of similar attributes other than cut, what percentage of customers would you think could pick their stone from the lineup?

As I feature H&A diamonds akin to what your'e talking about the honest answer is they may not see any difference. When we're giving an in-store presentation we turn people onto the various types of rounds we feature (when they express they are looking for a round diamond) and proceed to educate them to the science behind the beauty and then introduce various "personalities" within those diamonds with what we would consider to have "ideal" optics. We will never presume all people want the same "personality" as sure enough many people select diamonds that appeal to them that are not H&A or even cherry picked 57 facet ideal cuts.

Now let's take customers who are in the search for a diamond for their engagement. If you were to offer up a stone for each customer based upon what they are looking for and their budget, and then have them compare them to non h&a ideal stones, how often would the customer choose the CBI stone? If the other stones were allowed to be higher color/clarity/carat or a combination of them to match to the price of the CBI stone, would they still choose the CBI because the visual differences from the cut are profound enough to make them sacrifice on the other aspects?

Obviously you probably don't know the answers to these questions, but they are certainly fair to bring up for discussion and debate would you agree? We are here to help people find stones they find beautiful, and if a fair amount of people would indeed sacrifice some on cut to attain other attributes, there should be a balanced discussion that does not always place perfection in cut at the top of the list, high above all other factors.

You'd be surprised pfunk. As a seller of super ideal cut H&A's as well as cherry picked GIA XXX/AGS Ideals that cost less there are still a very good percentage of people who prefer the perfection of the H&A's and there is good reason for it too even when they don't necessarily see a difference. One of the primary reasons are the prices places like us and other online distributors sell them for in relation to what stores charge for products that are nowhere near the level of light performance combined with the 3d precision. People see and understand the value. It is important that a store knows how to present and educate at the same time too.

I do not say this to in any way diminish the quality of your product. You obviously feel you create a gread product, and considering the number of pleased customers you have I absolutely believe it. You deserve praise for the consistently beautiful diamonds you no doubt produce. Also, the push to gain more knowledge regarding diamond cut from you and others is the only way to advance, and that is to be commended. What I wonder about, though, is why we should push so many here towards the superideal cuts when "we aren't there yet" with the research. Perhaps a more balanced, accurate portrayal of the subtelty of differences between ideal and superideal would be better (i.e less of the "Maserati vs Nice chevy" type analogies).

On a personal note it has been an ambition of mine to take my video cameras behind the scenes to a cutting facility like Yoram's, etc. so consumers can in fact have a better understanding of the tedious and laborious man hours it takes to produce the precision products they cut over what is commonly being peddled on the market. You can't begin to compare the labor involved. I know as I've had many discussions with Yoram and our AVR/H&A cutters on the subject. If consumers were more educated to the process I believe they would have a much greater appreciation for these precision cut products.

Hope my .02c is of help.

Kind regards,
Rhino

 

[John P]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

Very good discussion being had here. A few things I want to touch on that stood out that I have been asking for awhile...

Good questions. I’ll try to get to all. Working on your CBI-specific items first.

2. I still wonder to what level does the optical symmetry have to extend to result in visual difference. Are minor defects in the h&a pattern grounds to rule out a stone as not good enough. I had posted a couple CBI stones in the thread before it was moved. Both had minor defects that would seem to disqualify from perfect h&a if going by the standards that whiteflash has on their website. Obviously they are still CBI diamonds and some of the best you can find, so what degree of perfection must be acheived if even these have minor defects?

Those are photo misalignments, not defects. It’s the Achilles heel of being a showroom brand.

We have not kept up with the internet-Joneses in photography. Not only are our photos ginormous (circa 2004 when all sellers made them ginormous) sometimes the camera-plane is off-parallel with the stage or table-facet. A single degree off-axis causes distortion and the illusion of problems. If Antwerp doesn’t catch it, the image goes to the High Performance Diamonds website. None of our other dealers use the photos. Wink picks up the phone and blasts me. I explain we’re a showroom brand. He tells me where I can put my showroom...

This is a retake I did for him just last week. Original on left. Better aligned in my setup on right.


This may be even more helpful. I made this video some time ago to answer the same question you're asking.

Problematic website image: http://table55.com/video/6355-misaligned-hearts.jpg
Video showing diamond in viewer: http://table55.com/video/6355-hearts-viewer.wmv

I have a whole treatise on this. Probably for another day, but the above is the summary.

The current tools are like driving a nail with a sledge hammer.

And it doesn’t help when the nail is hit sideways. For the record, we changed photographers in 2014 and have improved in that area.

As it relates to the topic of this thread: The above is yet another example - one separate from performance-nuances - of how 2D images are transcended by live viewing... That moment when a showroom shopper sees a precision-cut diamond in an anatomical viewer for the first time, especially a lighted ASET scope... It never, ever, fails to inspire a gasp, a “Wow!” or even a “Holy...(smokes)!”

 

[Rhino]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

John,

Really great post Pfunk.

My main concern is the thought that we can quantify performance in a metric that is meaningful to a broad swath of diamond consumers.
If we use cars as an analogy- everyone understands the difference between miles per gallon, and acceleration stats.
That makes both stats useful.
By hoisting the term "performance" on a diamond's cut, consumers without context will be mislead.

First statement: "Factually no laboratory has yet subdivided cut-quality components to anywhere near the level that color or clarity are subdivided. Doing this is already possible behind industry doors, but pressure from mass-manufacturers prevents public disclosure of greater cut detail for any given diamond."

I don't know who made this statement, but there's no truth behind it.
Yes, there are cutters claiming they have the "best" performance- and tools to back up the claim. If you agree with their idea of performance
The bigger issue is that there's simply not broad agreement which is the "best" performance.
That's why the term "performance" is completely not applicable to a consumer who wants to buy an engagement ring.
If two diamonds have the same selling price, but one is a "super ideal" 1.00, and the other is a "normal EX" 1.20ct which is noticeably larger, which performs better?

Sure there is truth behind it. Actually the AGS Light Performance Grade is dissected into a number of components no other lab does. 11 to be precise. As long as all the components don't add up to over .5 it'll acquire the "0" grade. Here are 2 examples.

 

[Rhino]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

Interesting John!
Of course we'd need to dig deeper than the most costly and least costly to get a more reliable sense of what is driving the prices.
And we'd also need to consider variables like overall spread, as well as the demographic- in other words, will J/SI1 diamonds follow the same price/cut patterns as D/VS1
You may be correct, I have not performed these comparisons.

Bryan- I'd be very interested in your take as well regarding the picture John posted.
Have either of you ever had a client who specifically asked for no patterning ( they don;t like hearts and arrows)

David,
I think John explained and illustrated the point very well. There is nothing not to agree with there.

I have never had a client ask specifically for "no patterning" in a round. I believe if anyone says they "don't like hearts and arrows" they probably have a misunderstanding about what it looks like in real life. If fact, some people looking at a hearts and arrows diamond are surprised that they don't really see the arrows pop out. Hearts and arrows images are captured with special filters that bring out the patterns and allow you to understand the level of optical precision of the diamond. It's a little like an x-ray of your hand. Your hand doesn't really look that way in real life but the image can helps determine why it hurts!

Good analogy Brian. If I would add to this ... with regards to people asking for and observing "patterning" ... the truth is even as perfect as the patterning is in precision products like H&A, AVC, AVR, Octavia, etc. the average layman and even the seasoned gemologist isn't going to *see* the pattern produced by the ASET exactly as it is shown in the ASET most of the time. As Brian pointed out consumers can't, in many instances "see" the arrows popping out. In some environments they will but in most they may not. In the ASET the arrows are blue which is supposed to be representative of head/body obstruction yet in many environments those facets are in fact lighting up ... and rather intensely I might add.

It is important to understand that EVERY diamond has patterning Dave. Every diamond has an "optical signature". Some are more chaotic than others while others are very uniform. IMHO the best lighting to see and determine this under is diffuse natural daylight with even distribution.

Peace,
Rhino

 

[tmorrow]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

I do wish AGSL would be a bit more welcoming to optical designs outside of their ray tracing "box" which was originally designed for round brilliants.

AGSL doesn't take your or mine tradeoff preferences into account in their cut grading. They must use repeatable metrics that they have proven correlate to a particular optical signature or potential brightness.

Anything like scintillation which which is a taste preference (do you like big, few and slow) or (do you like small, numerous and fast) is a taste preference so a rejection system like AGSL cannot be applied to it. I am pretty sure they have studied in depth scintillation and chosen not to include it in their cur grading as one is not "better" than the other.

Moreover sacrificing potential brightness (outside of their "box") in some areas for a particular optical pattern, or for more fire, or unique design, or size of flash is not something they will decide or rank. They will simply penalize for that loss of potential brightness as they should.

If they start catering to diamond cutters or making "exceptions" further away from theoretical optimal brightness potential they will be a marketing firm issuing marketing reports not a grading lab issuing grading reports.

 

[Karl_K]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

Whether someone chooses a tiny EGL lopsy fugs, a 2ct D FL Tiffany, a rich antique cut, a pear, an Octavia or something completely different doesn’t matter, as long as they do it with eyes wide open.

I feel the same way and as long as I have been on PS that was always my goal that diamond buyers make an informed decision.
Once they have the information it is up to them what they do with it.
As a consumer that included making an informed decision on the dealer as well as the diamond.
Since being in the trade trade I am a bit more restricted on commenting on dealers which is frustrating at times when I hear of a dealer bad mouthing informed consumers yet getting recommended.

 

[Karl_K]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

Thank you, Yoram, for bringing ETAS into the discussion. I have been thinking that it is presently the most effective way to understand and characterize diamond reflections to observers.

For those unfamiliar, the Cut Study group has a nice write up of what ETAS is here: http://www.cutstudy.com/cut/english/conference_posters/4.htm
With more visuals here:
http://www.cutstudy.com/cut/english/conference_posters/5.htm

ETAS is potentially much more helpful even to buyers because it would help them to see how differences in cut change the frequency and quality of reflections from all viewing angles and distances.

What are the limiting factors in making ETAS more widely available? Can one simply use a sarin scan to make an ETAS with the right software?

EDIT: Also, how significantly do the limitation errors of scans change the results of virtual ETAS? In other words, what aspects of a real ETAS is missed/mischaracterized in a virtual ETAS?

The scans aren't accurate enough.
The finer the details you try and get from a data-set the more accurate the data-set has to be to get good results.
If you take the same diamond and scan it 100 times on 25 different scanners of the same brand and type you will get very widely varying ETAS images.
Even using the same machine and taking 10 scans you would get different ETAS images.
With a mrb they would be better(close to each other) than fancies but not accurate enough for comparison one diamond to another when you get to the macro level.

 

[Rhino]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

You are right of course, PS is the place if someone is looking for high[est] level education. For pros as for consumers.
We try to tell the ongoing story where the laboratories stop for various reasons which non are innovation - advancement.
The beauty of this place is simply for the fact that we share this information.
You can do with it as you like.
The fact that products already exist that AGSL does not recognize as above their top range is just a fact, we will need to overcome such obstacles. Give us some time as we justify our advancement claims. It's not such an easy task but well worth it I believe. After all Diamond material is the most valuable substance on earth. It certainly deserves such high detailing crafted by human hands. Some definitely appreciate the efforts, I thank and salute those who do.
I disagree with everyone who claims optical precision is not quantifiable at this stage and time, it's true, we can't put numbers on them yet but we can definitely visualize any differences in ETAS. (Virtual ETAS is problematic as it depends on 3D scans which include limitation errors!). But real ETAS is the most sensitive tool available. We have been researching real ETAS for over a year now. It's complicated but even slight out of 3D symmetry will be noticed and recognized. Real ETAS conclusions can give us a good direction of LP potential. (You can see an old visual of a real ETAS in my avatar.)

This thread is focused towards round brilliants but if you take fancy shapes into account optical precision becomes more complicated and interesting.

We are still in the diaper stages of optical design as far as Diamonds are concern.
I do wish AGSL would be a bit more welcoming to optical designs outside of their ray tracing "box" which was originally designed for round brilliants.

Ain't this the truth. LOL and now you bring ETAS into the discussion.

Scintillation has been a pet study of mine for a long time and I've taken note of the ETAS in your avatar. The Helium or SarinHD scanner I believe is adequate to generate what is needed for the study me thinks. What say you?

 

[Rhino]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

Thank you, Yoram, for bringing ETAS into the discussion. I have been thinking that it is presently the most effective way to understand and characterize diamond reflections to observers.

For those unfamiliar, the Cut Study group has a nice write up of what ETAS is here: http://www.cutstudy.com/cut/english/conference_posters/4.htm
With more visuals here:
http://www.cutstudy.com/cut/english/conference_posters/5.htm

ETAS is potentially much more helpful even to buyers because it would help them to see how differences in cut change the frequency and quality of reflections from all viewing angles and distances.

What are the limiting factors in making ETAS more widely available? Can one simply use a sarin scan to make an ETAS with the right software?

EDIT: Also, how significantly do the limitation errors of scans change the results of virtual ETAS? In other words, what aspects of a real ETAS is missed/mischaracterized in a virtual ETAS?

It would be very interesting to compare Y's live ETAS with an ETAS from the Helium or Sarin HD scanner via Octonus. We may learn the scan is just fine.

 

[Karl_K]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

We may learn the scan is just fine.

If your curious run the test above.
10 scans same diamonds over 2 days.
1 RB diamond min painting or digging
1 RB diamond with more painting or digging.
1 RB diamond with less than optimal 3d symmetry.
Compare the etas images in DC.

 

[diagem]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

We may learn the scan is just fine.

If your curious run the test above.
10 scans same diamonds over 2 days.
1 RB diamond min painting or digging
1 RB diamond with more painting or digging.
1 RB diamond with less than optimal 3d symmetry.
Compare the etas images in DC.

No use, waste of energy.
The only way to confirm is with cuts well within the scopes of scanner error limitations. How many of those do you know in which you can compare with.

 

[KobiD]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

Great write up, and I love these technical discussions. One thing regarding the HOF though. You could easily also attribute their success to being involved with savvy marketting and brand naming. Its seen all too often that people spend the most under the impression that due to it costing more, it must be better.

HOF does have an intimidating marketing budget. But so do the zillions of “H&A” brands which come-and-go in chain-stores. They go because HOF has visual teeth and they do not. HOF is also offered in reputable stores which are frequently AGS members and highly-regarded in their communities. Kobi, with respect, inferring that all those pros are actually pulling the wool over their clients’ eyes seems disingenuous, as does inferring that every HOF owner was lulled by a false siren-song of marketing (forgive me if that’s not your inference). CBI now works with several former HOF dealers. I find them to be standup people who want the best for their clients.

Stepping back, my foremost interest since leaving full-time education has been empowering confident diamond buying on the internet, and supporting great service by local jewelers. For the record, dozens of former students have approached me for engagement diamond advice. What I do is give them top-to-bottom information, point them to proper sources to experience everything and let them decide. Whether someone chooses a tiny EGL lopsy fugs, a 2ct D FL Tiffany, a rich antique cut, a pear, an Octavia or something completely different doesn’t matter, as long as they do it with eyes wide open.

I wasn't inferring that anyone was having the wool pulled over their eyes, nor that all consumers are so shallow. Perhaps I should have initially stated that they could attribute some of their success towards it. Reading it again I do see it could be interpreted as me suggesting that their sole reason for success is purely based around marketting hype.. smoke and mirrors.

The second paragraph hits the nail on the head, and resembles what I have witnessed from most trade members here at PS. I feel you all act very professionally portraying unbiased information and sharing the wealth of information you have aquired.

I'm also not disagreeing that cut offers performance benefits. From a poor cut through to super ideal, there are no doubts that differences can be seen. At the pointier end of the spectrum we have tools that can help evaluate what might not be seen to the naked eye. When you consider perfomance (or particularly high performance) it almost always indicates a niche/specific market. Be it tooling, cars, wines, or diamonds. You will find a lot of people will be able to appreciate what they offer above the rest, but may not neccessarily be able to justify the premiums involved.

 

[John P]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

Squeezing in another post, before evening shenanigans.

1. John touched on how h&a is a bad term because it only applies to certain proportions. I had posted about this before the thread got moved I believe. If a stone has 82% LGF (maybe even 80-81%?), it won't be h&a but it can be cut just as precicesly. So folks who happen to find a diamond with big ugly clefts but great similarity throughout the hearts still have a diamond with great optical symmetry. In which case the question becomes which is more important? The symmetry or the proportions. If you have the stone with ugly clefts but still a great IS/ASET, what are you missing out from aside from meeting the requirements for "true h&a"?

I wouldn’t say you’re “missing out.” If you love the rich sparkle of an antique or transitional cut you won't be seeing that. But if you love the sizzle of a popping 60-60 you’re closer to it. All else being equal, the character of scintillation events moves from medium-to-large (more broadfire) as the lower halves are cut shorter and medium-to-small (more pinfire) as they’re cut longer.

55-615-4075-345-50: LH @ 5% graduation.


Major Asian and European labs issuing H&A Reports require 75-80%.- for those diamonds. You can see why; when accompanied with other Tolk measurements-in-range 75-80% lower halves produce traditional "Hearts & Arrows" patterns in the viewer. If you polish under 75% the reflections merge, producing "Darts & Arrows" (like lawn darts). If you go over 80% they turn into "Sharks-and-Arrows" (like shark fins). Yes, I made those up. They're as valid as "Hearts & Arrows" to me. Feel free to market using them, just buy me a beverage sometime... And if you don't think I'm funny, I'm going to ask you to lower your humor standards just a little for this post. kthx.

Getting back to visual teeth: The argument for 75-80% in Tolk-inspired makes with optical precision (aka H&A) is to facilitate balance of the visual components. Many cut-specialists feel the brightness and dispersion produced are complimented by the contrast pattern and virtual facet makeup lower halves in that range promote. We agree, and we actually target a slightly narrower range to facilitate our dealers’ ability to sell a distant CBI, based on the one the viewer is holding. Of course this is only one recipe. There is nothing “wrong or missing” with lower halves above or below this range, as long as the viewer likes the effect on scintillation. And this is, indeed, a detail which depends on live cognition, the environment and the viewer’s palate.

We could get very sidetracked (in a good way) about the plus-delta of interesting proportions-sets outside the usual geometry. Jonathan at GOG has been a long-time proponent of proprietary diamond cuts, harnessing the “power” of vintage looks coupled with modern optical precision. Take that to warp-speed and you have Karl_K and Yoram, bringing optical precision benefits to step cuts.

 

[MarionC]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

Terrific thread. One of the best ever. Thanks, everyone, for your ongoing education of the PS masses

 

[Karl_K]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

We may learn the scan is just fine.

If your curious run the test above.
10 scans same diamonds over 2 days.
1 RB diamond min painting or digging
1 RB diamond with more painting or digging.
1 RB diamond with less than optimal 3d symmetry.
Compare the etas images in DC.

No use, waste of energy.
The only way to confirm is with cuts well within the scopes of scanner error limitations. How many of those do you know in which you can compare with.

It will show a lot of variation in the etas for each diamond when compared to the ones of the same diamond.
The ones with painting/digging will show even more variation between the 10 scans than the other 2 because the scanners have problems with them.
It will show the scanners are not good enough, I am pretty confident of that.

 

[JoshuaNiamehr]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

+1 for this thread.

There are some physical measurement devices out there that are able to quantify light symmetry and other metrics, do you think they are part of the future of quantification of performance nuances?

 

[yssie]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

+1 for this thread.

There are some physical measurement devices out there that are able to quantify light symmetry and other metrics, do you think they are part of the future of quantification of performance nuances?

My thirty-second drive-by -
One area of discussion - pertaining to nuances - that I would love to see some experts chime in on is the impact of inclusions... Warts & Arrows, Mr. Pollard?

As far as I'm aware all scanning technologies used to quantify light return today consider only external facet structure - and perhaps external inclusions like naturals, etc. It is, however, indisputable that inclusions and body colour impact light return... and at some point the benefits of prioritizing Carat (which has already been introduced in this thread), Clarity, and Colour will outweigh the Cut Is King philosophy. Of course, ask ten people where that point is and you'll likely get ten different answers

My short story: I have a well-cut near-H&A 2.7 J MRB. It looks "white" at a glance, certainly, but the body colour is unmistakeable on inspection. I had the opportunity to compare it to a well-cut G MRB of eerily similar size and proportions, and... the G looked bigger, no doubt about it. The G was indisputably brighter, and my eyes did exactly what I'd expect and interpreted "brighter" as "whiter" - and "whiter" as "bigger". On PS the common advice to a new buyer looking to maximise size on a budget is to determine how far he can drop colour before the body tint becomes 'offensive' and make up the difference in carat and cut quality; I will happily argue that an 8.9mm G is going to look larger to some people than an otherwise identical 9.1mm J.

 

[Texas Leaguer]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

+1 for this thread.

There are some physical measurement devices out there that are able to quantify light symmetry and other metrics, do you think they are part of the future of quantification of performance nuances?

My thirty-second drive-by -
One area of discussion - pertaining to nuances - that I would love to see some experts chime in on is the impact of inclusions... Warts & Arrows, Mr. Pollard?

As far as I'm aware all scanning technologies used to quantify light return today consider only external facet structure - and perhaps external inclusions like naturals, etc. It is, however, indisputable that inclusions and body colour impact light return... and at some point the benefits of prioritizing Carat (which has already been introduced in this thread), Clarity, and Colour will outweigh the Cut Is King philosophy. Of course, ask ten people where that point is and you'll likely get ten different answers

My short story: I have a well-cut near-H&A 2.7 J MRB. It looks "white" at a glance, certainly, but the body colour is unmistakeable on inspection. I had the opportunity to compare it to a well-cut G MRB of eerily similar size and proportions, and... the G looked bigger, no doubt about it. The G was indisputably brighter, and my eyes did exactly what I'd expect and interpreted "brighter" as "whiter" - and "whiter" as "bigger". On PS the common advice to a new buyer looking to maximise size on a budget is to determine how far he can drop colour before the body tint becomes 'offensive' and make up the difference in carat and cut quality; I will happily argue that an 8.9mm G is going to look larger to some people than an otherwise identical 9.1mm J.

Yssie,
You make some important points regarding trade-offs of other C's. While it may be tangential to the primary topic of this thread it is important to recognize that clarity features (and to lesser extent color) can impact light performance. For instance, the concept of eye-clean can sometimes be viewed too simplistically. Some diamonds, particularly in the Si range and below, can be eye clean yet have diminished performance due to certain clarity characteristics, even when perfectly cut.

I would not say that these issues necessarily outweigh a "cut is king" philosophy because without excellent cutting you will not derive the full benefit of whatever size/color/clarity combo you happen to be looking at. But I will say that holding out for top cut quality without paying close attention to clarity features can result in taking two steps forward and one step back.

 

[tmorrow]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

+1 for this thread.

There are some physical measurement devices out there that are able to quantify light symmetry and other metrics, do you think they are part of the future of quantification of performance nuances?

My short story: I have a well-cut near-H&A 2.7 J MRB. It looks "white" at a glance, certainly, but the body colour is unmistakeable on inspection. I had the opportunity to compare it to a well-cut G MRB of eerily similar size and proportions, and... the G looked bigger, no doubt about it. The G was indisputably brighter, and my eyes did exactly what I'd expect and interpreted "brighter" as "whiter" - and "whiter" as "bigger". On PS the common advice to a new buyer looking to maximise size on a budget is to determine how far he can drop colour before the body tint becomes 'offensive' and make up the difference in carat and cut quality; I will happily argue that an 8.9mm G is going to look larger to some people than an otherwise identical 9.1mm J.

My appraiser in not so much detail said just about the same thing and there is truth to that. Higher more colourless appears brighter and bigger.

 

[Karl_K]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

On PS the common advice to a new buyer looking to maximise size on a budget is to determine how far he can drop colour before the body tint becomes 'offensive' and make up the difference in carat and cut quality; I will happily argue that an 8.9mm G is going to look larger to some people than an otherwise identical 9.1mm J.

to some people and everything the same being key phrases.
However not side by side even if everything was the same there are very very few people who would see the difference between 8.9mm and 9.1mm if everything else was the same.
However one ~8.9mm G vs2 is listed on PS for ~ $45000 for the same money you can go up to around 9.4mm with an i-vs2 or 10.2mm with a J-si1. The are not the same of course but are all 3 gia x with reasonable numbers.
That is enough to over come any difference color might cause.

 

[Rhino]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

+1 for this thread.

There are some physical measurement devices out there that are able to quantify light symmetry and other metrics, do you think they are part of the future of quantification of performance nuances?

Hi Josh,

It depends on what technology you're talking about. I have worked intimately with just about every technology out there from ASET, Bscope, Isee2, Sarine, sophisticated versions of IdealScope, Octonus Raytrace, OGI ray trace, etc. as well as correlating those results with real world observation. All of them have their strengths and all of them also have their limitations. We take the approach of "test all things, hold fast to that which is good". Technologies are great for communicating strengths and weakness of certain products but it is important that consumers know the limitations of them as well.

Regards,
Rhino

 

[diamondseeker2006]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

+1 for this thread.

There are some physical measurement devices out there that are able to quantify light symmetry and other metrics, do you think they are part of the future of quantification of performance nuances?

My thirty-second drive-by -
One area of discussion - pertaining to nuances - that I would love to see some experts chime in on is the impact of inclusions... Warts & Arrows, Mr. Pollard?

As far as I'm aware all scanning technologies used to quantify light return today consider only external facet structure - and perhaps external inclusions like naturals, etc. It is, however, indisputable that inclusions and body colour impact light return... and at some point the benefits of prioritizing Carat (which has already been introduced in this thread), Clarity, and Colour will outweigh the Cut Is King philosophy. Of course, ask ten people where that point is and you'll likely get ten different answers

My short story: I have a well-cut near-H&A 2.7 J MRB. It looks "white" at a glance, certainly, but the body colour is unmistakeable on inspection. I had the opportunity to compare it to a well-cut G MRB of eerily similar size and proportions, and... the G looked bigger, no doubt about it. The G was indisputably brighter, and my eyes did exactly what I'd expect and interpreted "brighter" as "whiter" - and "whiter" as "bigger". On PS the common advice to a new buyer looking to maximise size on a budget is to determine how far he can drop colour before the body tint becomes 'offensive' and make up the difference in carat and cut quality; I will happily argue that an 8.9mm G is going to look larger to some people than an otherwise identical 9.1mm J.

I agree with you, Yssie, about color. You never hear this mentioned on the forum as people are advising people to for low color stones. But I believe it to be very true regardless of size. Whiter stones are just brighter and show up more.

 

[Rockdiamond]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

To try and put this in a nutshell:
In the real world, cut grading is far more like clarity and color grading.
GIA, or AGSL describes the color of the diamond. No more, no less.
A D is not "better" than a J.
It does not "perform" better.
It has less color, that's it.

Take two hypothetical Si2 diamonds - one with a big crystal in the table over a facet on the pavilion which highlights it, and a second whose imperfection is tucked away in a spot that renders it invisible.
Both get the same grade- it's up to observers to distinguish.

Cut grading should be done in a similar manner- and in fact GIA's cut grade is broader than AGSL and is not "performance" based.
An argument can be made that GIA's grade is far too broad, allowing combinations we may not like as much as others.
People actually looking at diamonds will make choices, and not everyone will use the same factors in deciding which is the best cut.

This is not to take anything away from the science involved.
If the results are presented in an objective manner- as opposed to becoming a sales tool, all diamond consumers can benefit.
If cut grading and the science behind observing cut characteristics can develop in a more descriptive manner of grading, it would help a lot.
Spread is only one of the factors current "performance" testing either ignores, or places too little emphasis on.

Or sellers can push their own agendas and use "performance numbers" that abuse the term science to prove whatever diamond they're trying to sell performs better.

 

[John P]

Re: Quantifying Performance Nuances beyond ASET, H&A Photos,

The science brought to bear around the subject of diamond light performance is fairly new. While other groups and organizations have been and are making significant contributions to our ongoing understanding, AGS gets much of the credit for pushing the envelope on sophisticated diamond cut grading. But as John pointed out, it was GIA with their huge worldwide reach, whose eventual entry into reporting on cut quality really propelled the broader manufacturing sector to start doing better cutting.

We really should underscore this. I said it before; when GIA declared they’d introduce a cut grade for rounds some of the world’s major producers nearly lost their minds. GIA changed history and forced worldwide improvements. No one else could have done it, and they did... That gets lost in the noise sometimes, as the PS collective (correctly) dissects cut details, some of which fall in an area of GIA's metric which may not be as touted as others. It can seem anti-GIA. I am certain I'm not alone in saying that's patently not the case. They brought order to chaos in the only manner they practically could. It's cool that we can use it as a springboard for continuous improvement.