AGS Ideal Cut & Light Perf. RB vs Hearts & Arrows RB

[Lenapie]

Hello everyone! I'm a new user here at PriceScope and this is my first time posting. I have a question regarding round brilliants:

Question 1: Is there a visible different between a Round Brilliant that has AGS Ideal Cut & Ideal Light Performance and a Round Brilliant that's a Hearts & Arrows?

I've browsed a lot of vendors' websites and there seems to be a distinction between the two categories, such as at WF, they have Expert Selection vs ACA etc. There's a premium for the latter category and I'm just wondering if it's worth it to pay the extra. Ultimately, I know that's up to personal preference, but I wanted to hear the opinions of PSers, and whether or not there really is a detectable visible difference.

Another question I have is about colour. My e-ring (which I hope to post pics of soon, once I borrow a decent camera) is an AVC and it's a J colour. It is extremely white in pretty much all settings. I think I read somewhere that cushions show more body colour than do rounds, and that brings me to my 2nd question:

Question 2: For a round brilliant with Ideal Cut & Light Performance (maybe even Hearts & Arrows), can I expect a J colour to face up even whiter than a cushion, in general?

Thank you so much in advance!

 

[TC1987]

If the diamond's facet pattern is almost precise enough to be a H&A (it just misses the mark, in other words), you might have to do a side-by-side comparison to determine a difference. Good Old Gold used to post GemEx BrillianceScope reports for their diamonds, and I used those a lot to determine what I liked or didn't like about individual diamonds, all of which were H&A. http://www.goodoldgold.com/Technologies/BrillianceScope/BrillianceScopeStrengths/ Jon says that the BrillianceScope detects differences that the human eye can't see.

http://www.frantzdiamonds.com/diamond-education/diamond-precision.html claims you get more primary colors and less pastels and earth tones:

Benefits of Cut Precision

Cut Precision fine-tunes diamonds which already enjoy top performance. The better-defined contrast pattern creates sharper on-off scintillation and more primary colors in dispersion (less pastels and earth tones). Precision cutting maximizes the return of all available light, even in softer lighting conditions. This is a logical result of all of the facets, the tiny mirrors inside the diamond, brought into precise alignment with each other. Face up color is also improved when light gets in and out of a diamond with more intensity. This can be noted in many diamonds with above-average performance. High performance coupled with top cut precision enhances the effect even more.

H&A RB will wash tint better than cushions do. The RB is generally shallower and also doesn't have as high of a crown. You'd still see the J tint from the side, though. For a diamond 1ct or less, it shouldn't be much of a problem. If you don't mind tint, then maybe even look at K color H&A. I have a diamond that must be a L or M, but I never had it graded. It's H&A and faces up remarkably white in most lighting. Outdoors in overcast weather is the most unflattering lighting for it. Otherwise, it looks pale ivory.

 

[diagem]

I've browsed a lot of vendors' websites and there seems to be a distinction between the two categories, such as at WF, they have Expert Selection vs ACA etc. There's a premium for the latter category and I'm just wondering if it's worth it to pay the extra. Ultimately, I know that's up to personal preference, but I wanted to hear the opinions of PSers, and whether or not there really is a detectable visible difference.

Simple answer to your question in bold:

Depending on the accuracy/precision level of the individual cut pronouncing the H&A pattern, the higher the level, the more time & expertise it takes to achieve. If its worth to pay the extra will greatly depend on your cut priorities.

 

[blingbuyer]

I have been wondering this as well. All things the same if you have 2 diamonds, will one style look more brilliant/perform better than the other?

 

[Lorelei]

Hello everyone! I'm a new user here at PriceScope and this is my first time posting. I have a question regarding round brilliants:

Question 1: Is there a visible different between a Round Brilliant that has AGS Ideal Cut & Ideal Light Performance and a Round Brilliant that's a Hearts & Arrows?

I've browsed a lot of vendors' websites and there seems to be a distinction between the two categories, such as at WF, they have Expert Selection vs ACA etc. There's a premium for the latter category and I'm just wondering if it's worth it to pay the extra. Ultimately, I know that's up to personal preference, but I wanted to hear the opinions of PSers, and whether or not there really is a detectable visible difference.

Another question I have is about colour. My e-ring (which I hope to post pics of soon, once I borrow a decent camera) is an AVC and it's a J colour. It is extremely white in pretty much all settings. I think I read somewhere that cushions show more body colour than do rounds, and that brings me to my 2nd question:

Question 2: For a round brilliant with Ideal Cut & Light Performance (maybe even Hearts & Arrows), can I expect a J colour to face up even whiter than a cushion, in general?

Thank you so much in advance!

Hi Lena,

I think it's difficult to generalize really, with the two branded diamonds you mention above from WF, the ES aren't created equal so one ' near miss' ACA that becomes an ES might be comparable visually with the naked untrained eye to an ACA whereas another ES might not be. As DG says, some happily pay the premium for flawless cutting knowing they have a superbly crafted gem with supporting images, to others it may not be worth it.

As to AGS0 compared to H&A, some stones will be both, others will show some H&A patterning and be AGS0 but won't be considered the best examples of H&A, it depends. You might even find a stone with excellent patterning ( optical symmetry) not be AGS0.

Colour - again you can't really compare a fancy shape with a round brilliant as regards how colour will face up, also the size of the stones in question makes a difference and lab grading. Generally the larger the diamond the more the colour grade might show itself.

Sorry I can't be more specific but these are difficult questions to answer and I wouldn't want to mislead you.

 

[diagem]

.... As DG says, some happily pay the premium for flawless cutting knowing they have a superbly crafted gem with supporting images, to others it may not be worth it.

Hi Lorelei,

I'd like to add..., there is a wide range of precision levels in what we call Ideal or even super Ideal cuts.
At these levels we can clearly notice a difference when its pointed out to us. The more precise the cut the easier we can notice its optical anomalies.
The more precise the 3D symmetry the sharper its optical symmetry performance (OSP). Light show will be displayed in a more uniform and sharp appearance when in motion. (also in the faceup position but that has less of importance).
For example If the cut is focused on delivering *colorful fire events, they will be sharper more pronounced as the precision level gets higher.

I guess what I am trying to say, it is not a classic "peace of mind" issue. There is genuine added value at these levels of cutting.





*depending on its lighting environments.

 

[Karl_K]

*depending on its lighting environments.

That is the key to the whole answer.
Depending on lighting the answer is yes, no, maybe so.

 

[Lenapie]

.... As DG says, some happily pay the premium for flawless cutting knowing they have a superbly crafted gem with supporting images, to others it may not be worth it.

Hi Lorelei,

I'd like to add..., there is a wide range of precision levels in what we call Ideal or even super Ideal cuts.
At these levels we can clearly notice a difference when its pointed out to us. The more precise the cut the easier we can notice its optical anomalies.
The more precise the 3D symmetry the sharper its optical symmetry performance (OSP). Light show will be displayed in a more uniform and sharp appearance when in motion. (also in the faceup position but that has less of importance).
For example If the cut is focused on delivering *colorful fire events, they will be sharper more pronounced as the precision level gets higher.

I guess what I am trying to say, it is not a classic "peace of mind" issue. There is genuine added value at these levels of cutting.





*depending on its lighting environments.

Thank you so much for all the responses! It gives me a lot of information to think through and decide on my purchase. Knowing that there will be visible differences as far as fire goes (with the H&As giving off more precise/sharper fire) makes me lean towards the H&As.

Also good to know that RBs mask colour better! I'm perfectly fine with the J in the AVC, so most likely a J in a H&A will be fine, too. I'll probably look for Is and Js.

Between these ones, is there one that stands out? Or are they all pretty equal and I won't go wrong with any one?

http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-3225751.htm
http://www.briangavindiamonds.com/diamonds/diamond-details/1.665-j-vs2-round-diamond-ags-bl-104074030041
http://www.briangavindiamonds.com/diamonds/diamond-details/1.710-j-si1-round-diamond-ags-bl-104071999088

Again, thank you so much!

 

[Karl_K]

Between these ones, is there one that stands out? Or are they all pretty equal and I won't go wrong with any one?

http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-3225751.htm
http://www.briangavindiamonds.com/diamonds/diamond-details/1.665-j-vs2-round-diamond-ags-bl-104074030041
http://www.briangavindiamonds.com/diamonds/diamond-details/1.710-j-si1-round-diamond-ags-bl-104071999088

Again, thank you so much!

Per the forum rules Yoram and I can not answer that.
There are several prosumers that can help you with that.

 

[Lenapie]

Between these ones, is there one that stands out? Or are they all pretty equal and I won't go wrong with any one?

http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-3225751.htm
http://www.briangavindiamonds.com/diamonds/diamond-details/1.665-j-vs2-round-diamond-ags-bl-104074030041
http://www.briangavindiamonds.com/diamonds/diamond-details/1.710-j-si1-round-diamond-ags-bl-104071999088

Again, thank you so much!

Per the forum rules Yoram and I can not answer that.
There are several prosumers that can help you with that.

No worries, thank you so much for the helpful answers, Karl. I'll wait for some of the very knowledgeable Prosumers to help me out on this one.

 

[Karl_K]

Your welcome!

 

[diagem]

Knowing that there will be visible differences as far as fire goes (with the H&As giving off more precise/sharper fire) makes me lean towards the H&As.

For the record, my fire comment was as an example only and not aimed towards any of the options subject of this thread...
Again, at the top echelon of cuts, you can notice the difference if and when you are shown the differences.

 

[MelisendeDiamonds]

Knowing that there will be visible differences as far as fire goes (with the H&As giving off more precise/sharper fire) makes me lean towards the H&As.

For the record, my fire comment was as an example only and not aimed towards any of the options subject of this thread...
Again, at the top echelon of cuts, you can notice the difference if and when you are shown the differences.

I don't understand what you are saying here, it is awkwardly written. If a consumer can only notice if they are "shown the difference" it has very little value to that consumer or most consumers in general.

If by "shown the differences" you mean a comparison of one with a high level of cut precision versus one that is not, such that a consumer would readily notice a difference themselves, then that is where the premium is more substantiated and would be worthwhile to a greater number of consumers.

 

[Gypsy]

This might help: [URL='https://www.pricescope.com/community/threads/likelihood-of-finding-a-signature-super-ideal-diamond.174235/']https://www.pricescope.com/community/threads/likelihood-of-finding-a-signature-super-ideal-diamond.174235/[/URL]


Please read.

 

[Lenapie]

This might help: [URL='https://www.pricescope.com/community/threads/likelihood-of-finding-a-signature-super-ideal-diamond.174235/']https://www.pricescope.com/community/threads/likelihood-of-finding-a-signature-super-ideal-diamond.174235/[/URL]


Please read.

Thank you so much, Gypsy. That thread is very informative! From your explanation, it seems like the difference between the Ideals and Super Ideals (or Near Ideals vs Ideals, I suppose) lay more in the technical side of things. That probably contributes to a visible difference that not very many people can pick up just by looking at the diamond. I can certainly see in the ASET images that the Super Ideals have a crisper and more precise pattern, but I probably won't be able to detect the difference if I just saw the diamond without any images supporting it.

 

[Karl_K]

Hrere is the thing once you learn what to look for you cant unlearn it and hang around here long enough you will learn what to look for when viewing them.
Predicting if it will bug you is another story.

 

[Lenapie]

Hrere is the thing once you learn what to look for you cant unlearn it and hang around here long enough you will learn what to look for when viewing them.
Predicting if it will bug you is another story.

That's a good point you make, Karl. It's kind of like after seeing all the really, really well cut stones all the online reputable vendors have to offer, when I walk into a generic jewelry store in the mall, my reaction is:

 

[Karl_K]

Hrere is the thing once you learn what to look for you cant unlearn it and hang around here long enough you will learn what to look for when viewing them.
Predicting if it will bug you is another story.

That's a good point you make, Karl. It's kind of like after seeing all the really, really well cut stones all the online reputable vendors have to offer, when I walk into a generic jewelry store in the mall, my reaction is:

yep that is pretty much the way it is....

 

[diagem]

This might help: [URL='https://www.pricescope.com/community/threads/likelihood-of-finding-a-signature-super-ideal-diamond.174235/']https://www.pricescope.com/community/threads/likelihood-of-finding-a-signature-super-ideal-diamond.174235/[/URL]


Please read.

Thank you so much, Gypsy. That thread is very informative! From your explanation, it seems like the difference between the Ideals and Super Ideals (or Near Ideals vs Ideals, I suppose) lay more in the technical side of things. That probably contributes to a visible difference that not very many people can pick up just by looking at the diamond. I can certainly see in the ASET images that the Super Ideals have a crisper and more precise pattern, but I probably won't be able to detect the difference if I just saw the diamond without any images supporting it.

Not exactly..., Diamonds behave differently in various kind of environments...
You may not notice it if you don't really want to understand it but a person siting 25 feet across from you in a dimmed lit restaurant may suddenly notice something sparkling on your finger. Will that person notice the same on a similarly Ideal cut Diamond with not such tight parameters? Maybe so, but the higher the level of 3D optical light performance the sharper and more concentrated it's play of light.
I gave a simple example, but it could repeat itself anywhere and everywhere.
When a Diamond is cut to specific proportions and at the highest precision levels..., it definitely shows!!!
It's LP will have a more uniformed play of light, the various flash events will be larger and more defined especially it's virtual facet size flashes etc...
There is much more to it than my short explanation and/or example, but I am sure this will become a topic in the near future as precision levels go up!! We are still in its infancy

 

[Lenapie]

This might help: [URL='https://www.pricescope.com/community/threads/likelihood-of-finding-a-signature-super-ideal-diamond.174235/']https://www.pricescope.com/community/threads/likelihood-of-finding-a-signature-super-ideal-diamond.174235/[/URL]


Please read.

Thank you so much, Gypsy. That thread is very informative! From your explanation, it seems like the difference between the Ideals and Super Ideals (or Near Ideals vs Ideals, I suppose) lay more in the technical side of things. That probably contributes to a visible difference that not very many people can pick up just by looking at the diamond. I can certainly see in the ASET images that the Super Ideals have a crisper and more precise pattern, but I probably won't be able to detect the difference if I just saw the diamond without any images supporting it.

Not exactly..., Diamonds behave differently in various kind of environments...
You may not notice it if you don't really want to understand it but a person siting 25 feet across from you in a dimmed lit restaurant may suddenly notice something sparkling on your finger. Will that person notice the same on a similarly Ideal cut Diamond with not such tight parameters? Maybe so, but the higher the level of 3D optical light performance the sharper and more concentrated it's play of light.
I gave a simple example, but it could repeat itself anywhere and everywhere.
When a Diamond is cut to specific proportions and at the highest precision levels..., it definitely shows!!!
It's LP will have a more uniformed play of light, the various flash events will be larger and more defined especially it's virtual facet size flashes etc...
There is much more to it than my short explanation and/or example, but I am sure this will become a topic in the near future as precision levels go up!! We are still in its infancy

That just means MORE SPARKLES! And more sparkles is always awesome!

And I do understand there is a difference. By no means am I trying to down-play how great the really, really Ideal diamonds are. Their light performance is certainly sharper and more concentrated, as you stated. It's a matter of how much stronger/sharper vs an Ideal cut that is just slightly off the mark/with slightly less parameters. And whether or not that visible difference is worth the premium, which will always be a personal preference.

 

[diagem]

This might help: [URL='https://www.pricescope.com/community/threads/likelihood-of-finding-a-signature-super-ideal-diamond.174235/']https://www.pricescope.com/community/threads/likelihood-of-finding-a-signature-super-ideal-diamond.174235/[/URL]


Please read.

Thank you so much, Gypsy. That thread is very informative! From your explanation, it seems like the difference between the Ideals and Super Ideals (or Near Ideals vs Ideals, I suppose) lay more in the technical side of things. That probably contributes to a visible difference that not very many people can pick up just by looking at the diamond. I can certainly see in the ASET images that the Super Ideals have a crisper and more precise pattern, but I probably won't be able to detect the difference if I just saw the diamond without any images supporting it.

Not exactly..., Diamonds behave differently in various kind of environments...
You may not notice it if you don't really want to understand it but a person siting 25 feet across from you in a dimmed lit restaurant may suddenly notice something sparkling on your finger. Will that person notice the same on a similarly Ideal cut Diamond with not such tight parameters? Maybe so, but the higher the level of 3D optical light performance the sharper and more concentrated it's play of light.
I gave a simple example, but it could repeat itself anywhere and everywhere.
When a Diamond is cut to specific proportions and at the highest precision levels..., it definitely shows!!!
It's LP will have a more uniformed play of light, the various flash events will be larger and more defined especially it's virtual facet size flashes etc...
There is much more to it than my short explanation and/or example, but I am sure this will become a topic in the near future as precision levels go up!! We are still in its infancy

That just means MORE SPARKLES! And more sparkles is always awesome!

And I do understand there is a difference. By no means am I trying to down-play how great the really, really Ideal diamonds are. Their light performance is certainly sharper and more concentrated, as you stated. It's a matter of how much stronger/sharper vs an Ideal cut that is just slightly off the mark/with slightly less parameters. And whether or not that visible difference is worth the premium, which will always be a personal preference.

It's not a matter of how great the really, really Ideal Diamonds are....
And it has nothing to do with beauty.
It's a matter of fact and since many jewelers are touting the highest and brightest etc..., they should at least mean it as it does exist (on a small scale for now).
Diamonds are the most valuable substance on earth, this shouldn't mean cutters should aim only for the AGSL 0 LP threshold. They are valuable enough to deserve more if we keep touting the highest & brightest.

 

[WinkHPD]

This might help: [URL='https://www.pricescope.com/community/threads/likelihood-of-finding-a-signature-super-ideal-diamond.174235/']https://www.pricescope.com/community/threads/likelihood-of-finding-a-signature-super-ideal-diamond.174235/[/URL]


Please read.

Thank you so much, Gypsy. That thread is very informative! From your explanation, it seems like the difference between the Ideals and Super Ideals (or Near Ideals vs Ideals, I suppose) lay more in the technical side of things. That probably contributes to a visible difference that not very many people can pick up just by looking at the diamond. I can certainly see in the ASET images that the Super Ideals have a crisper and more precise pattern, but I probably won't be able to detect the difference if I just saw the diamond without any images supporting it.

On those occasions when I get to meet in person with a client, I like to set three to five diamonds in a slotted tray without saying anything at all about the diamonds. Most people will start by choosing the diamond they like the least and elimination that diamond from consideration. In my experience, it is nearly always the poorest cut diamond that is eliminated first. This is true, even if all the diamonds are AGS0 cut diamonds.

I once had a client who was going to look at diamonds with a retailer in another State. He called to tell me not to bother sending my stones as he just was not going to pay the premium when he could get the same AGS 0 cut grade for x% cheaper from a well known Internet vendor "famous" for its cheap prices. (The retailer he was going to had agreed to let him see all five diamonds at his store at one time even though that retailer was not providing any of the diamonds.)

I convinced him that since it was costing him nothing to see the diamonds that he was cheating himself if he did not at least see for himself that not all AGS 0 cut diamonds are equal.

When he arrived at the store, the jeweler had placed all five of the diamonds randomly on a slotted tray. When the client looked at the five diamonds, he immediately picked out two and said that they just did not sparkle like the others. If you guessed that they were the two diamonds from the "cheaper" vendor, you are absolutely correct.

Without the benefit of any supporting images, the client saw the visual difference immediately. My client ended up with one of my diamonds and the retailer got to make a nice mounting for the diamond that was chosen.

The AGS 0 cut grade is very hard to get and represents diamonds that have been cut for beauty. It still does not guarantee that these are the best cut diamonds possible. There are those very few that are the best of the best and most people can and will see the difference when those diamonds are placed side by side and they are told NOTHING about the diamonds. If it was a 50 - 50 deal I would say it was meaningless. However, when more than 80% to 90% of the time the more precisely cut diamond is chosen, I contend that it is a meaningful difference that can be seen and appreciated, with or without supporting images. There is just something magic about a diamond that has been cut to be the top of the top cut grade.

When you are buying something that is to be the symbol of your love, to be worn and appreciated forever, why would you buy anything but the most beautiful gem that you can afford, regardless of the size, color or clarity? In my opinion, it is the cut that rules!

Wink

 

[MelisendeDiamonds]

That just means MORE SPARKLES! And more sparkles is always awesome!

No. It isn't MORE sparkes it would be LESS sparkles. Tight optical symmetry keeps the average Virtual Facet size larger so there are LESS of them but they are larger and more noticeable..

 

[cflutist]

Ok, please define "virtual facet", my head is spinning.

 

[Paul-Antwerp]

That just means MORE SPARKLES! And more sparkles is always awesome!

No. It isn't MORE sparkes it would be LESS sparkles. Tight optical symmetry keeps the average Virtual Facet size larger so there are LESS of them but they are larger and more noticeable..

Please allow me to correct. The number of virtual facets is not the same as the number of sparkles potentially observed.

The smallest virtual facets are not necessarily observed by humans. You could argue that technically, they produce sparkles, but in essence, not for human eyes.

More important effect of bigger virtual facets is the likelihood increasing of Fire being observed. Another important effect is the intensity of the sparkle being higher.

Now, I leave it to others to explain the term 'virtual facet'.

Live long,

 

[WinkHPD]

Remember the last time you were sitting in a barber's or hairdresser's chair and saw yourself reflecting in two mirrors getting smaller and smaller into infinity.

Those were not real yous, they were virtual yous being reflected in virtual mirrors, each one smaller than the one before it.

Virtual facets are the same in a diamond. The 57 facets in a round brilliant cut diamond set up virtual mirrors within the diamond and you are seeing the results of those virtual mirrors when your diamond moves and some of the virtual facets turn on and others turn off, resulting in the scintillation that you love to see from your diamonds.

According to research done by the American Gem Society Laboratory, a one carat diamond will produce about 200,000 scintillation events as it is rotated over a 40 degree arc. The better cut the diamond, and the larger the initial virtual facets, the more of those scintillation events will actually be visible to the human eye. A top cut diamond might have between 12,000 and 14,000 eye visible scintillation events in a one carat diamond. A more poorly cut diamond will have thousands less as the smaller beginning virtual facets will much more quickly become too small for the human eye to visualize. (Larger diamonds can have larger starting virtual facets if they are cut well and thus will have even more eye visible scintillation events, with more flashes of both white and colored light, which is one of the reasons we like larger diamonds.)

I remember taking my grand children to the Learning Center here in Boise when they had an exhibit with many mirrors and all sorts of angles. It was amazing to stand between them and see yourself from so many different angles, getting smaller and smaller. I tired to imagine what it would be like to be inside a diamond, but it made my head hurt...

Wink

 

[cflutist]

Remember the last time you were sitting in a barber's or hairdresser's chair and saw yourself reflecting in two mirrors getting smaller and smaller into infinity.

Those were not real yous, they were virtual yous being reflected in virtual mirrors, each one smaller than the one before it.

Virtual facets are the same in a diamond. The 57 facets in a round brilliant cut diamond set up virtual mirrors within the diamond and you are seeing the results of those virtual mirrors when your diamond moves and some of the virtual facets turn on and others turn off, resulting in the scintillation that you love to see from your diamonds.

According to research done by the American Gem Society Laboratory, a one carat diamond will produce about 200,000 scintillation events as it is rotated over a 40 degree arc. The better cut the diamond, and the larger the initial virtual facets, the more of those scintillation events will actually be visible to the human eye. A top cut diamond might have between 12,000 and 14,000 eye visible scintillation events in a one carat diamond. A more poorly cut diamond will have thousands less as the smaller beginning virtual facets will much more quickly become too small for the human eye to visualize. (Larger diamonds can have larger starting virtual facets if they are cut well and thus will have even more eye visible scintillation events, with more flashes of both white and colored light, which is one of the reasons we like larger diamonds.)
I remember taking my grand children to the Learning Center here in Boise when they had an exhibit with many mirrors and all sorts of angles. It was amazing to stand between them and see yourself from so many different angles, getting smaller and smaller. I tired to imagine what it would be like to be inside a diamond, but it made my head hurt...

Wink

Ok, so a 2 ct would have larger starting virtual facets than a 1 ct, and a 3 ct would have even larger. How many eye visible scintillation events does each have? Is it proportional? Logarithmic?

 

[Texas Leaguer]

This is a really important discussion for this particular community. It may not be as interesting to the outside world because most consumers have not had their awareness raised to this level about the importance of cut craftsmanship. I will try not to repeat the astute comments made by others in the thread. Instead, I will try to help make the issue relatable with analogies.

Ideal relates to the engine - high horsepower if you will. Cut precision (hearts and arrows) relates to the "tuning" of that engine. You can have one without the other. But whatever the horsepower of the engine, fine tuning will enable it to generate optimal performance. And no matter how powerful the engine, if the faceting is not precise you will ultimatley lose performance. (e.g.The engine might be rated for 200 hp but if not tuned properly will only deliver 180). So you may get plenty of performance out of an AGS0 or even a GIA 3X, but neither will be all it can be without a very high level of faceting precision.

Is the difference obvious? No. Is it real? Yes.

As has already been stated, it is sometimes a case of performance visible at a distance. With more white and colored sparkle events possible of the size and crispness necessary to be observed by the human eye, a super ideal will be noticed and appreciated more often than a diamond cut to a lower level of precision.

So it's not as much about how well an ideal diamond performs. It's more about how much more you can get out of it by taking cut precision to the highest levels. In that sense, it is a bit of an acquired taste, like fine wine or fine cuisine. And it is also about knowing that the diamond is delivering everything possible for it's size, color and clarity.

 

[WinkHPD]

Remember the last time you were sitting in a barber's or hairdresser's chair and saw yourself reflecting in two mirrors getting smaller and smaller into infinity.

Those were not real yous, they were virtual yous being reflected in virtual mirrors, each one smaller than the one before it.

Virtual facets are the same in a diamond. The 57 facets in a round brilliant cut diamond set up virtual mirrors within the diamond and you are seeing the results of those virtual mirrors when your diamond moves and some of the virtual facets turn on and others turn off, resulting in the scintillation that you love to see from your diamonds.

According to research done by the American Gem Society Laboratory, a one carat diamond will produce about 200,000 scintillation events as it is rotated over a 40 degree arc. The better cut the diamond, and the larger the initial virtual facets, the more of those scintillation events will actually be visible to the human eye. A top cut diamond might have between 12,000 and 14,000 eye visible scintillation events in a one carat diamond. A more poorly cut diamond will have thousands less as the smaller beginning virtual facets will much more quickly become too small for the human eye to visualize. (Larger diamonds can have larger starting virtual facets if they are cut well and thus will have even more eye visible scintillation events, with more flashes of both white and colored light, which is one of the reasons we like larger diamonds.)
I remember taking my grand children to the Learning Center here in Boise when they had an exhibit with many mirrors and all sorts of angles. It was amazing to stand between them and see yourself from so many different angles, getting smaller and smaller. I tired to imagine what it would be like to be inside a diamond, but it made my head hurt...

Wink

Ok, so a 2 ct would have larger starting virtual facets than a 1 ct, and a 3 ct would have even larger. How many eye visible scintillation events does each have? Is it proportional? Logarithmic?

That information is above my pay grade. Maybe Pete Yantzer would know, he was deeply involved in the research at the AGSL. I lose track of them after about 100 and have to start over every time I try to count them...

Wink

 

[cflutist]

Oh and one more question.

Fancies and RBs have the same number of facets, but do RBs have more virtual facets due to their symmetry?

But on the other hand, princess cuts are symmetrical and don't perform like RBs? Their ASETs don't have as much red as RBs do.

Am I confused or what?