"Precision cut" - what does this mean?

[diagem]

Scanners used presently have a margin of error of 3-4 tenths of a degree..., meaning 40.8 is not necessarily 40.8
Symmetry grades are rising and have made a huge advance in the last decade.

Another limitation is labor costs..., a cutter can reach very good - excellent symmetry pretty easy if the primary stage of balancing the polished potential within the rough is done correctly...
Cutting generic cuts to these levels of symmetry is done regularly these days, the ISSUE is reaching these symmetry levels while being limited with extremely stringent angles & positions while applying them on asymmetrical fancy shapes. Thats where the cutters patience is taken to their limits..., Kenny, your Octavia was scanned over 500 times until it was successfully completed. I don't know many cutters with this kind of patience. Now only imagine the hours it takes..., sometimes it just doesn't pay as labor costs become a huge chunk of the overall value and go explain consumers why these branded cuts are super pricy.

That's the reason Octavia's are not cut in smaller sizes although I am playing around with the idea..., how else would I know if they have marketing potential unless I try.

 

[kenny]

..., Kenny, your Octavia was scanned over 500 times until it was successfully completed. I don't know many cutters with this kind of patience.

Wow.
What is "scanned"?

I've seen Youtube videos of cutters polishing on the wheel and lifing the stone up to loupe it, then they put it back on the wheel and repeat this many times.

Is this louping the scanning?
Or is there some piece of equipment you put the diamond into that scans it with a laser beam to measure it?
... and to scan it wouldn't you have to remove the diamond from the thingie that holds it while it is being polished?

If any of this is proprietary, don't answer.
I'm just nosey.

 

[diagem]

..., Kenny, your Octavia was scanned over 500 times until it was successfully completed. I don't know many cutters with this kind of patience.

Wow.
What is "scanned"?

I've seen Youtube videos of cutters polishing on the wheel and lifing the stone up to loupe it, then they put it back on the wheel and repeat this many times.

Is this louping the scanning?
Or is there some piece of equipment you put the diamond into that scans it with a laser beam to measure it?
... and to scan it wouldn't you have to remove the diamond from the thingie that holds it while it is being polished?

If any of this is proprietary, don't answer.
I'm just nosey.

Not proprietary just a whole lot of patience and calm nerves..., you are starting to understand the complexity of the process.
Scanning is done with scanners such as Helium, Sarin and Ogi. Every time the cutter replaces the stone from it's dop/tang he merely reassures he is cutting at the designated angle and if he swayed off he needs to realign himself with the specific angle required which usually means more scans. Kind of a catch 22 if you take the scanners margin of error.
Tricky hey

 

[diagem]

You asked for another example I gave you one.
I thought you might have cut the AVC as well but I guess you have chosen not to answer that one.

It's not another example, those two examples are actually opposites as far as objectives. One wishes it was a Lighter shade closer to colorless and the other wishes it was darker into Fancy territory. And the differences in the pictures you posted above clearly show that. Two different cutting objective on similar type material and facet design.
Regarding the second question..., since it was asked in public I feel obliged to acknowledge and answer.
Back in late 2008 when Jon (GOG) approached me and asked  if I would be willing to join efforts with him into developing a new consistently cut chunky cushion while combining both my knowledge in the Cushion cut arena and his extensive knowledge of Light behavior, I took his offer on but wished to stay behind the scenes for personal interests. Jon respected those wishes.

So to your question..., yes I am the cutter of the AVC you posted above.

Since I made the decision to slowly increase public exposure of my works, I would like to take this opportunity and inform of a new cushion brilliant I just completed the design and cutting of, this new cushion brilliant achieves the AGS 0 Light Performance grade while taking in account other important factors needed to compliment the light behavior of a cut Diamond.  I am hoping it will be released soon.

 

[kenny]

What does cushion brilliant mean?

 

[yssie]

DiaGem - thanks for your responses.

Regarding the optical signature - I would, for example, not consider WF ACA princesses to have a 'signature', I would consider Infinity princesses to have a signature. Both are brands. One follows a clearly templated model, the other has many more variables - number of chevrons, size of chevrons... and so my definition of signature is only as useful as what I know of the brand - which delves right back into RD's questions about what exactly a brand is.

I'm not trying to overcomplicate this idea - I do think it's an important part of this discussion, because brand recognition is so often an important consideration in "precision cutting" a stone! I'm thinking again of taking a given EC wireframe, say, and
1. Increasing the size keeping L/W same: obviously same signature by any definition.
2. Increasing L, keeping W same, or vice versa: slippery slope.
3. Gaussian style filter that increases or decreases facet-distance differences, keeping L/W same: not remotely similar in my mind
4. Increase or decrease the actual number of facets: different signature


I did not know that the error was so high w/ current technologies! It rather highlights the uselessness of quibbling over a single scan output variance of 0.1, 0.2deg. I also did not know that a design could require so much scanning and re-scanning!

Kenny your Octavia really was a labour of love - and probably a whole lot of cursing


The goal of the DBL and the AVC is very different - and that such differences can be achieved within the same shape w/ material with same/similar body colour is quite amazing! Thanks for elaborating on your goals with DBL, specifically - it is certainly a unique product. We've all seen that say dark grey and darker grey are less differentiable to the eye than white and light grey - even if numerically the difference is the same - why does less saturated colour specifically make it difficult to disperse the body colour *throughout the whole diamond*? What are the differences between less and more saturated colour in this regard?


Karl - thank you for chiming in! So it's fair to say that some of the variation is deliberate and some is not?

When you say that it's difficult to control the location of the facet rows w/ no guiding meet points, I assume it's in part because of the scanning error that you can't just say "I want P1 of X length at Adegrees from the girdle plane, P2 of Y length at Bdegrees from the P1 plane..." and be guaranteed to come out with precisely that. Can you tell us if you know going in what you want X & A, Y & B, Z & C, etc. to be - do you have an systematic ideal, or does it change from stone to stone based on size/colour/whatever?

 

[Karl_K]

Karl - thank you for chiming in! So it's fair to say that some of the variation is deliberate and some is not?

If I could get them as cookie cutter or in other words as much of a clone, one to the next as Paul's rounds I would.
That is never going to happen with any step cut in my opinion.

What we can do is make sure that each one meets my very high performance criteria and looks like a twin brother to another.

The rest of your question I am not comfortable answering other than to say there is a recipe of where the targeted location is at on the stone and the angle.

 

[yssie]

Karl - thank you for chiming in! So it's fair to say that some of the variation is deliberate and some is not?

If I could get them as cookie cutter or in other words as much of a clone, one to the next as Paul's rounds I would.
That is never going to happen with any step cut in my opinion.

What we can do is make sure that each one meets my very high performance criteria and looks like a twin brother to another.

Okay, I get. Thanks again

 

[Serg]

You asked for another example I gave you one.
I thought you might have cut the AVC as well but I guess you have chosen not to answer that one.

It's not another example, those two examples are actually opposites as far as objectives. One wishes it was a Lighter shade closer to colorless and the other wishes it was darker into Fancy territory. And the differences in the pictures you posted above clearly show that. Two different cutting objective on similar type material and facet design.
Regarding the second question..., since it was asked in public I feel obliged to acknowledge and answer.
Back in late 2008 when Jon (GOG) approached me and asked  if I would be willing to join efforts with him into developing a new consistently cut chunky cushion while combining both my knowledge in the Cushion cut arena and his extensive knowledge of Light behavior, I took his offer on but wished to stay behind the scenes for personal interests. Jon respected those wishes.

So to your question..., yes I am the cutter of the AVC you posted above.

Since I made the decision to slowly increase public exposure of my works, I would like to take this opportunity and inform of a new cushion brilliant I just completed the design and cutting of, this new cushion brilliant achieves the AGS 0 Light Performance grade while taking in account other important factors needed to compliment the light behavior of a cut Diamond.  I am hoping it will be released soon.

Hi Yoram,

re:I would like to take this opportunity and inform of a new cushion brilliant I just completed the design and cutting of, this new cushion brilliant achieves the AGS 0 Light Performance grade while taking in account other important factors needed to compliment the light behavior of a cut Diamond.

You welcome to add your new cushion to MSS list cushions with AGS PGS 0 Light performance grade.

see diamonds C1-С5

http://www.octonus.com/oct/mss/table.phtml

for proprietary cuts we do not publish scan reports and 3D models. we publish only photos and movies
see for example
http://www.octonus.com/oct/mss/diamC5.html
http://www.octonus.com/oct/mss/diamC4.html

 

[yssie]

Karl - thank you for chiming in! So it's fair to say that some of the variation is deliberate and some is not?

If I could get them as cookie cutter or in other words as much of a clone, one to the next as Paul's rounds I would.
That is never going to happen with any step cut in my opinion.

What we can do is make sure that each one meets my very high performance criteria and looks like a twin brother to another.

The rest of your question I am not comfortable answering other than to say there is a recipe of where the targeted location is at on the stone and the angle.

I appreciate you (and others) sharing what you are comfortable sharing

 

[Rockdiamond]

I think it's been an amazing discussion Yssie- thank you very much for starting it!
It shows that there can be many different types of cut considered "Excellent" for different virtues.
The comparisons showing two stones of the same color grade that look totally different was illustrative- it shows how much "power" a cutter can have- even within the same, somewhat narrow boundaries of antique Old Mine Brilliant.

Congratulations to Yoram on his new cut- and to Serg- I'd love to see those designs modified for, and cut with cape (light yellow) rough!

 

[pinkjewel]

You asked for another example I gave you one.
I thought you might have cut the AVC as well but I guess you have chosen not to answer that one.

It's not another example, those two examples are actually opposites as far as objectives. One wishes it was a Lighter shade closer to colorless and the other wishes it was darker into Fancy territory. And the differences in the pictures you posted above clearly show that. Two different cutting objective on similar type material and facet design.
Regarding the second question..., since it was asked in public I feel obliged to acknowledge and answer.
Back in late 2008 when Jon (GOG) approached me and asked  if I would be willing to join efforts with him into developing a new consistently cut chunky cushion while combining both my knowledge in the Cushion cut arena and his extensive knowledge of Light behavior, I took his offer on but wished to stay behind the scenes for personal interests. Jon respected those wishes.

So to your question..., yes I am the cutter of the AVC you posted above.

Since I made the decision to slowly increase public exposure of my works, I would like to take this opportunity and inform of a new cushion brilliant I just completed the design and cutting of, this new cushion brilliant achieves the AGS 0 Light Performance grade while taking in account other important factors needed to compliment the light behavior of a cut Diamond.  I am hoping it will be released soon.

Is this the Dynasty cut by any chance?

 

[diagem]

You asked for another example I gave you one.
I thought you might have cut the AVC as well but I guess you have chosen not to answer that one.

It's not another example, those two examples are actually opposites as far as objectives. One wishes it was a Lighter shade closer to colorless and the other wishes it was darker into Fancy territory. And the differences in the pictures you posted above clearly show that. Two different cutting objective on similar type material and facet design.
Regarding the second question..., since it was asked in public I feel obliged to acknowledge and answer.
Back in late 2008 when Jon (GOG) approached me and asked  if I would be willing to join efforts with him into developing a new consistently cut chunky cushion while combining both my knowledge in the Cushion cut arena and his extensive knowledge of Light behavior, I took his offer on but wished to stay behind the scenes for personal interests. Jon respected those wishes.

So to your question..., yes I am the cutter of the AVC you posted above.

Since I made the decision to slowly increase public exposure of my works, I would like to take this opportunity and inform of a new cushion brilliant I just completed the design and cutting of, this new cushion brilliant achieves the AGS 0 Light Performance grade while taking in account other important factors needed to compliment the light behavior of a cut Diamond.  I am hoping it will be released soon.

Hi Yoram,

re:I would like to take this opportunity and inform of a new cushion brilliant I just completed the design and cutting of, this new cushion brilliant achieves the AGS 0 Light Performance grade while taking in account other important factors needed to compliment the light behavior of a cut Diamond.

You welcome to add your new cushion to MSS list cushions with AGS PGS 0 Light performance grade.

see diamonds C1-С5

http://www.octonus.com/oct/mss/table.phtml

for proprietary cuts we do not publish scan reports and 3D models. we publish only photos and movies
see for example
http://www.octonus.com/oct/mss/diamC5.html
http://www.octonus.com/oct/mss/diamC4.html

Hi Sergey, please tell me more?

 

[diagem]

You asked for another example I gave you one.
I thought you might have cut the AVC as well but I guess you have chosen not to answer that one.

It's not another example, those two examples are actually opposites as far as objectives. One wishes it was a Lighter shade closer to colorless and the other wishes it was darker into Fancy territory. And the differences in the pictures you posted above clearly show that. Two different cutting objective on similar type material and facet design.
Regarding the second question..., since it was asked in public I feel obliged to acknowledge and answer.
Back in late 2008 when Jon (GOG) approached me and asked  if I would be willing to join efforts with him into developing a new consistently cut chunky cushion while combining both my knowledge in the Cushion cut arena and his extensive knowledge of Light behavior, I took his offer on but wished to stay behind the scenes for personal interests. Jon respected those wishes.

So to your question..., yes I am the cutter of the AVC you posted above.

Since I made the decision to slowly increase public exposure of my works, I would like to take this opportunity and inform of a new cushion brilliant I just completed the design and cutting of, this new cushion brilliant achieves the AGS 0 Light Performance grade while taking in account other important factors needed to compliment the light behavior of a cut Diamond.  I am hoping it will be released soon.

Is this the Dynasty cut by any chance?

It was not officially released yet.....

 

[Serg]

You asked for another example I gave you one.
I thought you might have cut the AVC as well but I guess you have chosen not to answer that one.

It's not another example, those two examples are actually opposites as far as objectives. One wishes it was a Lighter shade closer to colorless and the other wishes it was darker into Fancy territory. And the differences in the pictures you posted above clearly show that. Two different cutting objective on similar type material and facet design.
Regarding the second question..., since it was asked in public I feel obliged to acknowledge and answer.
Back in late 2008 when Jon (GOG) approached me and asked  if I would be willing to join efforts with him into developing a new consistently cut chunky cushion while combining both my knowledge in the Cushion cut arena and his extensive knowledge of Light behavior, I took his offer on but wished to stay behind the scenes for personal interests. Jon respected those wishes.

So to your question..., yes I am the cutter of the AVC you posted above.

Since I made the decision to slowly increase public exposure of my works, I would like to take this opportunity and inform of a new cushion brilliant I just completed the design and cutting of, this new cushion brilliant achieves the AGS 0 Light Performance grade while taking in account other important factors needed to compliment the light behavior of a cut Diamond.  I am hoping it will be released soon.

Hi Yoram,

re:I would like to take this opportunity and inform of a new cushion brilliant I just completed the design and cutting of, this new cushion brilliant achieves the AGS 0 Light Performance grade while taking in account other important factors needed to compliment the light behavior of a cut Diamond.

You welcome to add your new cushion to MSS list cushions with AGS PGS 0 Light performance grade.

see diamonds C1-С5

http://www.octonus.com/oct/mss/table.phtml

for proprietary cuts we do not publish scan reports and 3D models. we publish only photos and movies
see for example
http://www.octonus.com/oct/mss/diamC5.html
http://www.octonus.com/oct/mss/diamC4.html

Hi Sergey, please tell me more?

Hi Yoram,
What type additional information do you need?

 

[diagem]

You asked for another example I gave you one.
I thought you might have cut the AVC as well but I guess you have chosen not to answer that one.

It's not another example, those two examples are actually opposites as far as objectives. One wishes it was a Lighter shade closer to colorless and the other wishes it was darker into Fancy territory. And the differences in the pictures you posted above clearly show that. Two different cutting objective on similar type material and facet design.
Regarding the second question..., since it was asked in public I feel obliged to acknowledge and answer.
Back in late 2008 when Jon (GOG) approached me and asked  if I would be willing to join efforts with him into developing a new consistently cut chunky cushion while combining both my knowledge in the Cushion cut arena and his extensive knowledge of Light behavior, I took his offer on but wished to stay behind the scenes for personal interests. Jon respected those wishes.

So to your question..., yes I am the cutter of the AVC you posted above.

Since I made the decision to slowly increase public exposure of my works, I would like to take this opportunity and inform of a new cushion brilliant I just completed the design and cutting of, this new cushion brilliant achieves the AGS 0 Light Performance grade while taking in account other important factors needed to compliment the light behavior of a cut Diamond.  I am hoping it will be released soon.

Hi Yoram,

re:I would like to take this opportunity and inform of a new cushion brilliant I just completed the design and cutting of, this new cushion brilliant achieves the AGS 0 Light Performance grade while taking in account other important factors needed to compliment the light behavior of a cut Diamond.

You welcome to add your new cushion to MSS list cushions with AGS PGS 0 Light performance grade.

see diamonds C1-С5

http://www.octonus.com/oct/mss/table.phtml

for proprietary cuts we do not publish scan reports and 3D models. we publish only photos and movies
see for example
http://www.octonus.com/oct/mss/diamC5.html
http://www.octonus.com/oct/mss/diamC4.html

Hi Sergey, please tell me more?

Hi Yoram,
What type additional information do you need?

MMS list of cushions?
What's the objective of this list?

 

[Serg]

You asked for another example I gave you one.
I thought you might have cut the AVC as well but I guess you have chosen not to answer that one.

It's not another example, those two examples are actually opposites as far as objectives. One wishes it was a Lighter shade closer to colorless and the other wishes it was darker into Fancy territory. And the differences in the pictures you posted above clearly show that. Two different cutting objective on similar type material and facet design.
Regarding the second question..., since it was asked in public I feel obliged to acknowledge and answer.
Back in late 2008 when Jon (GOG) approached me and asked  if I would be willing to join efforts with him into developing a new consistently cut chunky cushion while combining both my knowledge in the Cushion cut arena and his extensive knowledge of Light behavior, I took his offer on but wished to stay behind the scenes for personal interests. Jon respected those wishes.

So to your question..., yes I am the cutter of the AVC you posted above.

Since I made the decision to slowly increase public exposure of my works, I would like to take this opportunity and inform of a new cushion brilliant I just completed the design and cutting of, this new cushion brilliant achieves the AGS 0 Light Performance grade while taking in account other important factors needed to compliment the light behavior of a cut Diamond.  I am hoping it will be released soon.

Hi Yoram,

re:I would like to take this opportunity and inform of a new cushion brilliant I just completed the design and cutting of, this new cushion brilliant achieves the AGS 0 Light Performance grade while taking in account other important factors needed to compliment the light behavior of a cut Diamond.

You welcome to add your new cushion to MSS list cushions with AGS PGS 0 Light performance grade.

see diamonds C1-С5

http://www.octonus.com/oct/mss/table.phtml

for proprietary cuts we do not publish scan reports and 3D models. we publish only photos and movies
see for example
http://www.octonus.com/oct/mss/diamC5.html
http://www.octonus.com/oct/mss/diamC4.html

Hi Sergey, please tell me more?

Hi Yoram,
What type additional information do you need?

MMS list of cushions?
What's the objective of this list?

MMS=Master Stone Set (4.2 Establishing set of etalons for testing human perception of diamond appearance and beauty)

it is part of long term project . Please See more in below links

http://www.octonus.com/oct/projects/NextDiamond.pdf

http://www.octonus.com/oct/projects/strategies.phtml

 

[NARRISHKEIT]

You welcome to add your new cushion to MSS list cushions with AGS PGS 0 Light performance grade.

see diamonds C1-С5

http://www.octonus.com/oct/mss/table.phtml

Why do diamonds C1-C6 have a listed PGS grade of 1 not 0?

 

[NARRISHKEIT]

Can you find another one just or similar to it?

Similar in terms of vintage facet design and YZ color grade.
I have seen other examples of yellow vintage faceted cushion designs (one 3Ct+ one with an intense yellow) but based on your comments I think you cut them all.

One wishes it was a lighter shade closer to colorless and the other wishes it was darker into Fancy territory. And the differences in the pictures you posted above clearly show that.

Thats a very interesting point thank-you for sharing it. If those were the primary goals wouldn't it have been better (if the timing and availability of rough ) to use the rough you used on the AVC (pre August 2010) for the DBL (pre April 2011) one and vice versa.

The DBL one Strong Blue Fluoro, thick to extremely thick girdle and in the vintage faceted style which did not receive the fancy grade
despite cutting efforts to increase the light path and improve color uniformity.

The AVC despite optimized CA/PA for strong high angle light return from edge to edge and shorter light path which decreases color still received the YZ grade.

I would guess the body color of the rough used for the AVC was darker than what was used for the DBL.

Your thoughts?

Two different cutting objective on similar type material and facet design.

 

[Serg]

You welcome to add your new cushion to MSS list cushions with AGS PGS 0 Light performance grade.

see diamonds C1-С5

http://www.octonus.com/oct/mss/table.phtml

Why do diamonds C1-C6 have a listed PGS grade of 1 not 0?

discount for Durability. we graded Cushion in AGS PGS as round cut. I do not see any real problem with durability for these cushions

 

[Rockdiamond]

Can you find another one just or similar to it?

Similar in terms of vintage facet design and YZ color grade.
I have seen other examples of yellow vintage faceted cushion designs (one 3Ct+ one with an intense yellow) but based on your comments I think you cut them all.
It's not a safe assumption that every vintage cushion is cut by Yoram. There are other cutters making these antique style stones today- plus I'd guess that enterprising cutters will copy successful designs.Yoram is at the forefront, but there are others.

One wishes it was a lighter shade closer to colorless and the other wishes it was darker into Fancy territory. And the differences in the pictures you posted above clearly show that.

Thats a very interesting point thank-you for sharing it. If those were the primary goals wouldn't it have been better (if the timing and availability of rough ) to use the rough you used on the AVC (pre August 2010) for the DBL (pre April 2011) one and vice versa.

The DBL one Strong Blue Fluoro, thick to extremely thick girdle and in the vintage faceted style which did not receive the fancy grade
despite cutting efforts to increase the light path and improve color uniformity.
The GIA grades of Fancy Light Yellow, and Y-Z are so very close. In other words, there's nothing that makes one "Fancy" and the other "plain" other than the name of a GIA grade. Anyone looking at the Y-Z cut for color will see a yellow diamond. IN terms of color uniformity, although Old Mine Brilliant is not intrinsically the best for even color distribution, Yoram's design breaks new ground.
Below you can see one of Yoram's stones cut for Yellow next to Radiant Cuts - Yoram's stone got Fancy Light Yellow from GIA. NO question the color distribution is different-which I feel accentuates the old style charm



The AVC despite optimized CA/PA for strong high angle light return from edge to edge and shorter light path which decreases color still received the YZ grade.

I would guess the body color of the rough used for the AVC was darker than what was used for the DBL.

Your thoughts?

Two different cutting objective on similar type material and facet design.

 

[NARRISHKEIT]

You welcome to add your new cushion to MSS list cushions with AGS PGS 0 Light performance grade.

see diamonds C1-С5

http://www.octonus.com/oct/mss/table.phtml

Why do diamonds C1-C6 have a listed PGS grade of 1 not 0?

discount for Durability. we graded Cushion in AGS PGS as round cut. I do not see any real problem with durability for these cushions

So the girdle thickness at the thick part is too thin <2.2% so it gets a deduction on all of them?

 

[yssie]

I would guess the body color of the rough used for the AVC was darker than what was used for the DBL.

Your thoughts?

This is a good question - where does the switch from grading body colour (like a chip of the diamond is knocked off...) and apparent face-up colour happen?

A Y/Z could be a Fancy and vice versa, sounds like, depending on apparent face-up colour due to cutting... what about a "W/X-worthy" body colour stone - could a given piece of rough be cut into say a W/X EC/RB *or* a Fancy radiant? I had always assumed that for marginal stones they first looked at body colour in the way D-Zs are graded, if that's under a certain hue/tone/saturation it's automatically still in the D-Z scale... if this is indeed the method they're still using subjective people who can have varying opinions, of course. Is it?

 

[Rockdiamond]

Great question Yssie!
Instead of D-Z, then Fancy Colors, let's change the names of the grades to a numerical scale, for the purposes of this discussion.
D=1
G=4
J=9
N=50
Y-Z=60-65
Fancy Light Yellow 66=74
Fancy Vivid Yellow at it's very best =100

I think this is more representative of reality.
Light yellow stones don't have to be called "fancy" by GIA to be recognized as fancy color diamonds on the finger.

I'm not sure of GIA's exact methodology regarding grading face up, or through the pavilion on the U-V, W-X, and-Y-Z range.
But I will say that assigning these grades is ,IMO, far more difficult than grading the difference between Fancy Light, and Fancy Yellow.
This discussion highlights the fact that it makes a big difference in the way the rough is used.
Without a doubt, cutting this lighter yellow rough presents a lot of options- and challenges.
Round is far less commonly the "best answer"

 

[yssie]

Great question Yssie!
Instead of D-Z, then Fancy Colors, let's change the names of the grades to a numerical scale, for the purposes of this discussion.
D=1
G=4
J=9
N=50
Y-Z=60-65
Fancy Light Yellow 66=74
Fancy Vivid Yellow at it's very best =100

I think this is more representative of reality.
Light yellow stones don't have to be called "fancy" by GIA to be recognized as fancy color diamonds on the finger.

I'm not sure of GIA's exact methodology regarding grading face up, or through the pavilion on the U-V, W-X, and-Y-Z range.
But I will say that assigning these grades is ,IMO, far more difficult than grading the difference between Fancy Light, and Fancy Yellow.
This discussion highlights the fact that it makes a big difference in the way the rough is used.
Without a doubt, cutting this lighter yellow rough presents a lot of options- and challenges.
Round is far less commonly the "best answer"

Thanks RD... I now have a whole host of questions. PSer Amethyste has a giant (5ct) W/X pear. The body colour is whatever it is, but given the size (so extra colour saturation) and small facet patterns (so extra colour saturation), I am wondering *how* they decided to keep it, or the two cushions brought up earlier in this thread, in the D-Z/1-65 range instead of 66-74 if face-up appearance comes into play w/ stones of this body colour..

Why? Are there are just fewer examples to practice on, or are the delineations less clear for some reason?

 

[stone-cold11]

Scale seems to be too uneven?

 

[diagem]

DiaGem - thanks for your responses.

The goal of the DBL and the AVC is very different - and that such differences can be achieved within the same shape w/ material with same/similar body colour is quite amazing! Thanks for elaborating on your goals with DBL, specifically - it is certainly a unique product. We've all seen that say dark grey and darker grey are less differentiable to the eye than white and light grey - even if numerically the difference is the same - why does less saturated colour specifically make it difficult to disperse the body colour *throughout the whole diamond*? What are the differences between less and more saturated colour in this regard?

Thats exactly what both pics display in the first page of this thread. The AVC carries an unobstructed pavilion view from the table allowing maximum unobstructed LR reflected directly to the viewers eyes displaying a whiter face-up appearance.
On the DBL cushion those pavilion mains are specifically aimed to obstruct the view with the true color of the material.

Naturally the lighter the color of the rough material, the more white light return will win over the material's genuine yellow color.

Hope I am explaining myself clearly as I am having a bad English day .

 

[Rockdiamond]

Scale seems to be too uneven?

Actually, the scale is uneven.
The reason is that trying to judge the absence of color is WAAAY easier than judging the presence of color. So the lower down on the scale, the wider the grades.

Yssie- GIA's color grading methodology stinks- but it's the best we have.
IMO stones should be graded face up- especially in the lower color ranges.
A cutter would most certainly check face up color.
Since the rough for these stones is a fraction of colorless- or darker - rough- cutters have had more of an opportunity to experiment.
Pear shapes are currently in demand in fancy colors- and bring higher prices than Radiant/CMB's- which would certainly play a part in decision making of a cutter.


To again return to the original point - branded stones.
Yoram- or Serg- what would your position be if another enterprising cutter copied one of your designs? Do you think it would be possible to prevent it?
Would you expect others to copy it? If, for example, Octavia took off- would you expect to see others cutting it?

 

[Serg]

David,

re:Yoram- or Serg- what would your position be if another enterprising cutter copied one of your designs?

inevitable harm

reo you think it would be possible to prevent it?

not completely . It is real big problem. Patents are very expensive and not helpful

re: Would you expect others to copy it?

Yes, I saw it for our cut( but can not proof it)

re: If, for example, Octavia took off- would you expect to see others cutting it?

Not now

 

[Rockdiamond]

David,

re:Yoram- or Serg- what would your position be if another enterprising cutter copied one of your designs?

inevitable harm
Really Serg? I disagree. If a cut is copied, it might actually help the inventor of the cut- as I see it, people will want "the original"- the Radiant Cut has shown this to be the case

reo you think it would be possible to prevent it?

not completely . It is real big problem. Patents are very expensive and not helpful
Agreed

re: Would you expect others to copy it?

Yes, I saw it for our cut( but can not proof it)

re: If, for example, Octavia took off- would you expect to see others cutting it?

Not now

Why?