H&A performance

[DavR]

Hello everyone,

In an effort to better understand the impact optical symmetry plays on the performance of a diamond I have decided to create a new post. This is largely in response to a less that optimal image with a diamond I was/am considering. I wanted to bring this into a separate topic in case anyone has insight into this but normally doesn’t pay attention to the countless "compare these diamonds" threads.

It seems pricescopes evaluation is extremely strict (which is great and as it should be), and looking at most if not all of the H&A on JA and WF in the carat range .50 - .70 would not pass as true H&A. Looking at the comparison chart on Highperformancediamonds suggests basically all of the H&A advertised would fall below the Perfect and well above Above - Average. Is this an artifact of the difficulty of cutting perfect symmetry increasing as size decreases?
In terms of performance what does this translate to?
Consider the case with 2 AGS Ideal 000 diamonds:
Would a perfect cut be distinguishable with the eye versus Above-Average cut? What about a perfect cut versus the majority of H&A for sale?

Would a non-perfect heart still be considered a top performer compared to non H&A diamonds given similar proportions?

Thank you for your input,

D


Another example is seen here: http://www.goodoldgold.com/4Cs/NewCutGrading/OpticalSymmetry/
This example of H&A looks much more in line with the majority of cuts I have seen, but would be regarded as less than Perfect or perhaps even not a true H&A by pricescopes(Brian Gavin's) definition.

 

[haagen_dazs]

Would a non-perfect heart still be considered a top performer compared to non H&A diamonds given similar proportions?

Thank you for your input,

hi i think you meant "nonH&A compared to H&A" am i right?

if so, let me just briefly share my experience
at the end of the day, when you do go down and start comparing diamonds with your own eyes, i have realized that both types of diamonds are very very close (top 1% and 1 to 1.5% of diamonds)
it is really not easy to see the difference to the general consumer.

 

[DavR]

Interesting formating error, the correct unicode character shows on my screen....

I feel your observation gets to the point of this discussion, it seems to me that the ideal H&A labeled as perfect is more of a concept than an actual practical indicator of performance quality, when compared other stones cut in the range of H&A but not perfect. I could be complety wrong in this assumption, but that is exactly why I started this thread.

 

[stone-cold11]

Experts are still undecided if H&A will perform better.

Visibly, you will not be able to see the Hearts image once the stone is mounted.

 

[Lula]

Date: 10/13/2009 4:21:08 PM
Author: Stone-cold11
Experts are still undecided if H&A will perform better.


Visibly, you will not be able to see the Hearts image once the stone is mounted.

I agree with Stone. You may not be able to see the difference in performance with your naked eye.

But I would add that you do not want to pay a premium for a "near hearts" stone. If a stone is advertised as H&A, make sure you get visual proof (hearts images) that demonstrates that it is truly an H&A.

 

[Allison D.]

A precise H&A pattern may not have a direct impact on a diamond's performance; it's likely more a correlative relationship.

It takes planning, precision, and superb craftsmanship to achieve the most stringent H&A standards; it's not accidental. Because of the significant labor investment to do this, it makes sense that one would want to invest that time only on diamonds that are top-performers, too.

While a crisp H&A isn't a guarantee of top-performance, it certainly makes sense that most of them would qualify.

 

[Allison D.]

Date: 10/13/2009 3:13:26 PM
Author:DavR

It seems pricescopes evaluation is extremely strict (which is great and as it should be), and looking at most if not all of the H&A on JA and WF in the carat range .50 - .70 would not pass as true H&A.

DavR, I can''t speak for anyone else''s inventory, but I can assure you that our H&A stones do indeed meet the ''true'' H&A standards. Our ACA line was developed based on the exact same standards as published in the Pricescope H&A tutorial, and the criteria remain the same to earn our brand.

We do also carry non-H&A stones, but we don''t offer them as H&A.

 

[WinkHPD]

Date: 10/13/2009 4:21:08 PM
Author: Stone-cold11
Experts are still undecided if H&A will perform better.

Visibly, you will not be able to see the Hearts image once the stone is mounted.

Hey Stone Cold, how are you doing.

Some of us experts believe that the larger virtual facets formed by better optical symmetry will make the diamond perform better than one with more numberous and smaller virtual facets, particularly when many of the additional facets are below the limit of discerment by the unaided human eye.

I do not remember the exact numbers, nor do I have time to look them up right now, but let us say that these numbers I am about to give are approximately correct as given to us by Peter Yantzer at the Dallas Infinity Symposium. I published a series of videos from those presentations that can be seen somewhere on this site if someone knows how to look them up better than I do.

Better yet, let''s just say these numbers are approximations from this old man''s brain and reserve the right for me to be wildly off in the actual numbers, but that the concept is correct.

Let us say a one carat princess cut has approximately 180,000 virtual facets which create scintillation events as Peter calls them that are measurable as you rotate the princess cut through a 45 degree from 90 degrees each way. If it is a well cut princess with excellent optical symmetry and two chevrons on the pavilion, lets say that approximately six to seven thousand of these virtual facets are visually detectable to the unaided human eye. Ten to twenty of them might actually be large scintillation events, a larger number medium events and the majority of the eye visible events are small scintillation events.

Now take a princess cut that is the same size, and make it with three chevrons. Now you may have three or four large events, or even no large events and more medium to small events and tens of thousands of more events below the limits of detectability of the human eye.

Dang, I am talking princess cuts and you are talking H&A. The principle is the same. The less perfect the optical symmetry, the more smaller events, the fewer larger events, and the more events that are too small to be detected by the human eye.

It is felt by many experts that this is detectable to the unaided eye and that thus the H&A stones do perform better. However, this has yet to be proven via scientific testing so you have other experts who disagree with this comment.

I suspect that eventually we will have definitive proof one way or the other, but even were it to be proved that you could not see the difference with the eye, there will still be those, myself included, who like the idea that the quality standards on the cutting are so high that they exceed the ability of the eye to detect it. I also suspect that by the time we are able to prove this one way or the other that several million more arguments will take place and years shall pass before our eyes and hearts...

Heck, maybe we will be lucky enough that we can never prove it, only believe that we know it, and thus we will be able to discuss and argue it forever, I kind of like the idea of that.

Wink

 

[DavR]

I don't mean to insult the products of the various companies so please do not take it that way. I am essentially trying to get at the heart of the matter(pun not intened). As a novice consumer I am trying to understand the boundaries of what constitues a real H&A diamond. Perhaps my real confusion is based on the standards defined in articles defining optical symetry. For example (I hope this is allowed to post images from these sites, if not I will remove them , and instead link the page).
For example both of these have hearts that are considered perfect:
from http://journal.pricescope.com/Articles/65/1/Hearts-and-Arrows-Diamonds-and-The-Basics-of-Diamond-Cutting.aspx

 

[stone-cold11]

Wink, that is a long reply. Ya, I know about the AGS research, still not conclusive right, or AGS will be able to start handing out grades for H&A.

I will get back to you soon with my custom design, got side-tracked with work recently...

 

[DavR]

but differ in some respects:
from http://www.highperformancediamonds.com/index.php?page=education-precision

 

[stone-cold11]

OP, one thing to remember, H&A is a measure of optical symm to the traditional H&A shape. An optically symm stone might not necessary display a traditional H&A image, can still have great optical performance.

 

[DavR]

I will say without a doubt anything labled H&A looked nothing like the average picture above, but again very few looked exactly like either of the perfect examples, but all were close. So my point is how close to that 'perfect' constitutes a true H&A, and does it really matter that it is not 'perfect' once you get close enough. And again I have a sample bias on the smaller hearts from .55-.7 in the 3k or less range.


"The less perfect the optical symmetry, the more smaller events, the fewer larger events, and the more events that are too small to be detected by the human eye. " Wink
That is a very interesting idea - So while there is a point in which cut angles come together to form the Perfect H&A and at that point the large events will be maximized. As you move down the specturm of H&A precision the number of large events decreases. If that is correct that could be measured quanitativly, assuming the technology exists.

 

[haagen_dazs]

Date: 10/13/2009 5:23:30 PM
Author: Stone-cold11


I will get back to you soon with my custom design, got side-tracked with work recently...

what are you making ? =0

 

[stone-cold11]

Date: 10/13/2009 5:44:19 PM
Author: haagen_dazs

Date: 10/13/2009 5:23:30 PM

Author: Stone-cold11

I will get back to you soon with my custom design, got side-tracked with work recently...

what are you making ? =0

Just my engagement ring.

 

[Lula]

Date: 10/13/2009 5:44:19 PM
Author: haagen_dazs

Date: 10/13/2009 5:23:30 PM

Author: Stone-cold11



I will get back to you soon with my custom design, got side-tracked with work recently...

what are you making ? =0

Date: 10/13/2009 5:44:19 PM
Author: haagen_dazs

Date: 10/13/2009 5:23:30 PM

Author: Stone-cold11



I will get back to you soon with my custom design, got side-tracked with work recently...

what are you making ? =0

Yes, Stone, please 'fess up! Is there a thread somewhere about this Wink project?

To the OP, there are many vendors who sell stones labeled as H&A. It has, unfortunately, become part of the marketing of diamonds and the true meaning of H&A is often lost.

Stones with pristine optical symmetry and perfect H&A patterning do exist; I own one. It's a Crafted by Infinity stone that I chose because I loved its proportions, its superior cut (I looked at its Helium report and admired the low deviation scores); and the beauty and accuracy of its H&A patterning.

I've also seen examples of other stones from several other vendors that display perfect H&A patterning.

If you look at enough online listings for stones, your eye will become very good at discerning the perfect H&A from the near-perfect H&A. It's up to you how much that matters to you, i.e., how long you want to spend looking for a stone, and how much value you place on perfect H&A.

I believe I can see the difference, but I am a "cut fanatic" who loves math/physics and appreciates the sheer artistry that it takes to cut a stone to these levels of preciseness.

There are others who don't value this level of cut quality; their stones are beautiful as well.

Yes, you should pay for the best cut quality you can afford, but there are several "levels" within cut quality, as you are learning, and each consumer should decide for him/herself where their priorities lie.

It can be confusing, I know. My best advice to you is, if you haven't already done so, spend some time looking at the sites that provide thorough information on their stones -- H&A, ASET, Helium, IS, etc., and you will see that Alj's post above is spot-on: those stones that have super-precise H&A also tend to have dynamite ASET, IS images and very tight cut quality (shown in the Helium report). So there is a correlation.

Some people can see tip-top cut and value it; some people can't see it and choose to buy a stone that is "well-cut" instead.

 

[YoungPapa]

Date: 10/13/2009 5:25:52 PM
Author: DavR
So my point is how close to that ''perfect'' constitutes a true H&A, and does it really matter that it is not ''perfect'' once you get close enough.

Davr,

I can''t speak to the second half of your question, but as to the first you might want to start with the H&A standards recently published by HRD:

Hearts & Arrows by HRD Antwerp

 

[WinkHPD]

Date: 10/13/2009 5:25:52 PM
Author: DavR

I will say without a doubt anything labled H&A looked nothing like the average picture above, but again very few looked exactly like either of the perfect examples, but all were close. So my point is how close to that ''perfect'' constitutes a true H&A, and does it really matter that it is not ''perfect'' once you get close enough. And again I have a sample bias on the smaller hearts from .55-.7 in the 3k or less range.


''The less perfect the optical symmetry, the more smaller events, the fewer larger events, and the more events that are too small to be detected by the human eye. '' Wink

That is a very interesting idea - So while there is a point in which cut angles come together to form the Perfect H&A and at that point the large events will be maximized. As you move down the specturm of H&A precision the number of large events decreases. If that is correct that could be measured quanitativly, assuming the technology exists.

I wish it were just that easy.

It also has to do with the size of the diamond, the shape, the Old European cuts for exambple have huge short Pavilion main facets with HUGE virtual facets that produce extraordinary dispersion and large scintillation events. A one carat diamond will have more large and medium events than a quarter carat and will itself be dwarfed in the number of the larger events from a two or three carat diamond.

Every time I think I have it figured out, and I have been working on it for most of my adult life, then some other factor comes to play.

This is a debillitating hobby as it grabs your soul teases you mercilessly with beauty while you try to figure out why. Then another thing catches your eye and you love that too. With Diamonds and gems, when you come to play, bring time and money and a serious desire never to sleep again...

Wink

 

[DavR]

Thank you Jim, that is exactly what I was looking for.


Yea no kidding Wink, I’ve only been truly researching diamonds for less than a week and yet I've put over 70 hours into it (to the detriment of my thesis). I'd like to think I have learned all the basics and some of the more intricate aspects, but topics such as this really demonstrate just how complex and interesting this field is. From what I have gathered, and I could be mistaken, but the real information age on diamonds is only a few years old. I really see the companies embracing the flow of information (the venders on Pricescope) really pulling even farther ahead of the pack.


Quick question for anyone that knows, when grading H&A what do unbalanced V's suggest and why do they not lead to a disqualification. I think this is the main discrepency seen among all of the H&A I have looked at and is the catalyst for this discussion.

 

[Todd Gray]

Date: 10/13/2009 5:23:08 PM
Author: DavR
Perhaps my real confusion is based on the standards defined in articles defining optical symmetry.

Part of the confusion might be due to many of the images used within various articles and tutorials are either drawings and/or photographs which have been edited in photo editing software to create a perfectly symmetrical image for purposes of illustration... e.g. anybody who thinks those swimsuit models in the Sports Illustrated Swim Suit edition are 'real' (that perfect out of the box) needs a lesson in photo editing

A few years ago I walked into a friends 'shop' and he had a poster of the Barbie Twins up on the wall... I admired it for a moment and then he started slobbering all over it to the point where I felt compelled to point out all the places they'd been edited, including pointing out that "you do realize that her leg couldn't possibly bend like that, right? It's been edited, here, there, here, here, here..." at which point he tore down the poster, wadded it up and tossed it in the trash while exclaiming "why did you have to ruin it?"

I feel the same way when I look at the H&A images I see in a lot of tutorials... I get why they're so perfect for 'illustration purposes' but things aren't so perfect in real life.

 

[DavR]

Haha what a good friend, that is really funny. I think you are spot in your statement. To continue your analogy from my perspective: The poster of the photoshopped girls is all I have ever seen, while the nearest comparison is some zombie girl (above average cut or below on the comparison chart - they look terrible in comparison). I had no real basis in which to judge besides the two extremes.

The Hearts & Arrows by HRD Antwerp really includes most of the information that I was wanting and felt was lacking from the various websites. I would even suggest adding some or all of this information to the websites for the inquisitive people like me.

Using this criteria it is very clear that all of the H&A listed as such on the pricescope venders sites are 'True' H&A. The mysteriously exempt from disqualification V's however do show the greatest variability which would be expected given its exempt status.

 

[Todd Gray]

Date: 10/13/2009 7:07:24 PM
Author: DavR
Haha what a good friend, that is really funny. I think you are spot in your statement. To continue your analogy from my perspective: The poster of the photo-shopped girls is all I have ever seen, while the nearest comparison is some zombie girl (above average cut or below on the comparison chart - they look terrible in comparison). I had no real basis in which to judge besides the two extremes.

This is the problem with using illustrations instead of actual photographs for the tutorials, but at the same time the illustrations more accurately depict what a person can see when looking through a scope when all eight hearts or arrows can be taken in by the human eye. The problem seems to develop when a camera is involved because the depth of field (or something) alters how each of the eight structures appears.

Not to thread jack you or anything, but since you brought up Zombies... Zombie Land was an excellent B-grade Flick!

 

[DavR]

Just an early morning bump to see if anyone knows the answer to this question:

When grading H&A what do unbalanced V''s suggest and why do they not lead to a disqualification of H&A status?

 

[DavR]

Still interested in an answer, so Ill bump this back up again.

 

[Paul-Antwerp]

You misunderstand the HRD-guidelines. For each factor, a stone can get a penalty, and if the sum of these penalties surpasses a certain level, the stone is not graded H&A by HRD. In this case, the stone cannot get to this level on this aspect alone, but its penalty might add to the level being surpassed.

Live long,

 

[DavR]

Exactly my point. Why is it the case that unbalanced V''s can not disqualify a H&A grade by themselves, when every other aspect evaluated can. For example, lets say I have a diamond that gets a perfect score in every other category, but the V''s are all out of wack, that would still be considered an H&A.

As an aside question are the V''s the pavillion facets?

 

[John P]

Date: 10/27/2009 12:14:59 PM
Author: DavR
Still interested in an answer, so Ill bump this back up again.

Without writing a treatise a clarification should be made:

Your topic is "H&A PERFORMANCE." This has little to do with most H&A grading systems.

The HRD system is a good independent reference but it judges H&A PRECISION (not performance). While they frequently comingle a great H&A pattern does not necessarily guarantee top performance - as a certain beloved Aussie constantly reminds people.

In technical terms Wink took the time to write posts which address your topic.

But now...

When grading H&A what do unbalanced V's suggest and why do they not lead to a disqualification of H&A status?

...I am going to reverse course and give an answer on the PRECISION topic (not performance). It may not be completely germane but it may be interesting.

There are four different potential causes for unbalanced Vs in the hearts:

#1 Inconsistenty in lower halves
#2 Inconsistency in lower halves plus pavilion/crown mains
#3 A tilted table
#4 Photography

#4 is easiest to address. Inexperienced or time-pressed photographers may not get the lens of the camera perfectly level with the plane of the platform on which the diamond is resting. Even a fraction of a degree will make a difference with the hundreds of reflections happening in such a tiny object. When slightly "off" the main patterns - which draw most light - can still resolve, but the minor facet reflections can appear off. This is why I preach (again and again) that 2D photos are nice but...just like clarity...and just like color...it is impossible to decisively evaluate 3D precision of a diamond without having it in hand. Anyone who has seen two diamonds in a H&A viewer, one with the highest level of precision and one that comes close, in a high quality H&A viewer knows the differences are far more evident in real life, with stereo vision & depth perception, than what is possible in 2D photography - and no "cheating" of photos can occur in real life.

#3 [tilted table info] A slight degree can influence the Vs and girdle area. Larger degrees can distort the entire pattern.

#2 and #1 have to do with the brillianteering of the diamond. The left hearts image below is of a diamond modeled with perfect wireframe precision. In the right image I altered just 5 of the 16 lower halves by up to 0.3 of one degree. Even this microscopic adjustment, leaving all of the other facets perfectly intact, created the different balance in the Vs.

It's a reminder of how incredibly well-crafted diamonds of top-precision that stand up to thorough examination are... But with that said (and kudos given) the influence of precision on PERFORMANCE is another subject.

 

[John P]

Date: 10/27/2009 1:06:44 PM
Author: DavR

As an aside question are the V's the pavillion facets?

Vs are primarily dependent on lower halves.

Date: 10/27/2009 1:06:44 PM
Author: DavR

Exactly my point. Why is it the case that unbalanced V's can not disqualify a H&A grade by themselves, when every other aspect evaluated can. For example, lets say I have a diamond that gets a perfect score in every other category, but the V's are all out of wack, that would still be considered an H&A.

By HRD's system there are "low" to "high" penalties for this (see below) but they recognize that many diamonds submitted for the grade may not meet the standards. With today's advanced tools there are a lot of diamonds which show some level of H&A as a by-product of the modern cutting process - I call these "Happy Accident" H&As. Rejecting Vs would result in a standard too strict for a lot of those Happy Accidents, which could mean less diamonds submitted by large manufacturers.

That raises another topic relating to the "why?" of superideal diamond cutting, as conceived by the original Japanese who developed and cut them, but we probably already have enough going on here already.

(HRD graphic)

 

[DavR]

Thank you John for your in-depth reply - that was extremely interesting. I realize that the thread topic has changed from the original purpose as I have moved from the subjective performance evaluations of H&A and learned much more about the H&A grading process.

Are the 'hearts' influenced by such small degree changes as the V's are? If not would it be safe to assume that the leeway unbalanced V's have in terms of outright disqualification is primarily due to the extremely minor degree changes causing noticeable alteration of the optimal V pattern?



Edit: Ah it seems my assumption is correct given your last post. I’m always willing to learn more about the fascinating subject of diamonds, so feel free to elaborate on the "why" of super ideal cutting if you feel like it as it seems that all of my questions about H&A have now been fully answered.

 

[John P]

Date: 10/27/2009 2:05:47 PM
Author: DavR

Are the 'hearts' influenced by such small degree changes as the V's are? If not would it be safe to assume that the leeway unbalanced V's have in terms of outright disqualification is primarily due to the extremely minor degree changes causing noticeable alteration of the optimal V pattern?

You're welcome. As you deduced, the general answers are "no" and "yes" respectively... But the answer to the first question also depends on many factors including the size and quality/construction of the H&A viewer. Cheap viewers hide a lot and I see oversaturation frequently used to compensate for poor lighting, viewer dynamics or distortion in photos (I'll bang on the "live assessment" drum again here

...I’m always willing to learn more about the fascinating subject of diamonds, so feel free to elaborate on the 'why' of super ideal cutting...

You may get more than you want. This topic is the area of specialty that drew me into the diamond business - because it spans technical, aesthetic and philosophical ground. As a romantic art-loving history buff with OCD I was hooked.

I've been fortunate enough to learn firsthand from some amazing people and if you're not careful I can talk about it ad nauseum.

For now I find that I took longer than intended to generate the stuff above so I'll try to find time in the next days. It's a favorite subject. It's nice to see someone asking detailed questions.