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Evaluating spread for princess cut

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Bunnifer

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I'm trying to evaluate how to compare the spreads of these two diamonds and whether the more expensive one is worth the price difference. Please help!

#1: 1.5 I SI2 $7600
Dimensions: 6.30 x 6.34
Table: 71.57
Depth: 74.01

#2: 1.6 H SI2 $9900
Dimensions: 6.47 x 6.46
Table: 62.77
Depth: 74.31

Both are AGS0, so cut equals out. The representative (of a reputable vendor) said that the I faces up totally white and he can't really tell the difference between the two unless they're both being compared in a white tray. IRL, he thinks the I and H are comparable. (Sorry, I'm being slightly vague here b/c I don't want my diamonds snatched up!)

Thoughts from the venerable peanut gallery???

Attached is a picture of the 1.5 princess. (I'm still figuring out how to attach more than one pic to a post!)

1.5-Princess.jpg
 

oldminer

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Multiply the length times the width of each and you will see that in this case the heavier stone also has the larger square surface view face-up. To adjust for weight would give you a way to relate the efficiency of cut, but it hardly matters, if they both look great, the size visible is what counts. One is larger looking than the other without any doubt or complex formula.
 

diagem

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Date: 1/3/2007 3:48:05 PM
Author:Bunnifer
I''m trying to evaluate how to compare the spreads of these two diamonds and whether the more expensive one is worth the price difference. Please help!

#1: 1.5 I SI2 $7600
Dimensions: 6.30 x 6.34
Table: 71.57
Depth: 74.01

#2: 1.6 H SI2 $9900
Dimensions: 6.47 x 6.46
Table: 62.77
Depth: 74.31

Both are AGS0, so cut equals out. The representative (of a reputable vendor) said that the I faces up totally white and he can''t really tell the difference between the two unless they''re both being compared in a white tray. IRL, he thinks the I and H are comparable. (Sorry, I''m being slightly vague here b/c I don''t want my diamonds snatched up!)

Thoughts from the venerable peanut gallery???

Attached is a picture of the 1.5 princess. (I''m still figuring out how to attach more than one pic to a post!)
I am a big fan of smaller tables.
But somehow the 1.60 seems to have a smaller table than 62%..., but i have a problem with the depth%
By the way..., how deep can a princess go, and still be considered a "top" AGS-0 cut???
And both these diamonds are "not" equally cut!!! Look at the facet size...

It doesnt mean they are not great looking gems, i just think you can an equally good stone atleast with a bit better spread...
 

Bunnifer

Shiny_Rock
Joined
Sep 26, 2006
Messages
227
Hmmmm...OK, so multiplying the length by the width, I get:

#1: 6.30*6.34 = 39.942
#2: 6.47*6.46 = 41.796

So, the difference is approx. 1.85mm2 -- is the 2mm2 worth the 2k price difference?
 

Bunnifer

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Joined
Sep 26, 2006
Messages
227
Date: 1/3/2007 4:37:29 PM
Author: DiaGem
Date: 1/3/2007 3:48:05 PM

Author:Bunnifer

I''m trying to evaluate how to compare the spreads of these two diamonds and whether the more expensive one is worth the price difference. Please help!


#1: 1.5 I SI2 $7600

Dimensions: 6.30 x 6.34

Table: 71.57

Depth: 74.01


#2: 1.6 H SI2 $9900

Dimensions: 6.47 x 6.46

Table: 62.77

Depth: 74.31


Both are AGS0, so cut equals out. The representative (of a reputable vendor) said that the I faces up totally white and he can''t really tell the difference between the two unless they''re both being compared in a white tray. IRL, he thinks the I and H are comparable. (Sorry, I''m being slightly vague here b/c I don''t want my diamonds snatched up!)


Thoughts from the venerable peanut gallery???


Attached is a picture of the 1.5 princess. (I''m still figuring out how to attach more than one pic to a post!)
I am a big fan of smaller tables.

But somehow the 1.60 seems to have a smaller table than 62%..., but i have a problem with the depth%

By the way..., how deep can a princess go, and still be considered a ''top'' AGS-0 cut???

And both these diamonds are ''not'' equally cut!!! Look at the facet size...


It doesnt mean they are not great looking gems, i just think you can an equally good stone atleast with a bit better spread...
Interesting, DiaGem...I never thought to compare the facet sizes. Now that you mention it, I think the 1.6 has smaller facets than the 1.5? Also, how do you know (or why do you think) that the 1.6 has a smaller table than 62%?

Can you find a diamond with a bit better spread? All of the ones I''ve seen have LESS spread than these! Is it the nature of cutting princesses or have all the good ones already been snatched up?
 

diagem

Ideal_Rock
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Oct 21, 2004
Messages
4,930
Date: 1/3/2007 4:59:35 PM
Author: Bunnifer

Date: 1/3/2007 4:37:29 PM
Author: DiaGem

Date: 1/3/2007 3:48:05 PM

Author:Bunnifer

I''m trying to evaluate how to compare the spreads of these two diamonds and whether the more expensive one is worth the price difference. Please help!


#1: 1.5 I SI2 $7600

Dimensions: 6.30 x 6.34

Table: 71.57

Depth: 74.01


#2: 1.6 H SI2 $9900

Dimensions: 6.47 x 6.46

Table: 62.77

Depth: 74.31


Both are AGS0, so cut equals out. The representative (of a reputable vendor) said that the I faces up totally white and he can''t really tell the difference between the two unless they''re both being compared in a white tray. IRL, he thinks the I and H are comparable. (Sorry, I''m being slightly vague here b/c I don''t want my diamonds snatched up!)


Thoughts from the venerable peanut gallery???


Attached is a picture of the 1.5 princess. (I''m still figuring out how to attach more than one pic to a post!)
I am a big fan of smaller tables.

But somehow the 1.60 seems to have a smaller table than 62%..., but i have a problem with the depth%

By the way..., how deep can a princess go, and still be considered a ''top'' AGS-0 cut???

And both these diamonds are ''not'' equally cut!!! Look at the facet size...


It doesnt mean they are not great looking gems, i just think you can an equally good stone atleast with a bit better spread...
Interesting, DiaGem...I never thought to compare the facet sizes. Now that you mention it, I think the 1.6 has smaller facets than the 1.5? Also, how do you know (or why do you think) that the 1.6 has a smaller table than 62%?

Can you find a diamond with a bit better spread? All of the ones I''ve seen have LESS spread than these! Is it the nature of cutting princesses or have all the good ones already been snatched up?
Regards to the table, it just looks to small for a 62%.
Thats only based on my visual opinion, i may be completely wrong.

I dont know exactly the new parameters for AGS-0 princesses, and i am one who agrees with "perfect" or "ideal" Fancy cut diamonds.
I did see plenty of gorgeous princess cuts that their depths were in the 60%''s

My problem with deep princess cuts is that the weight is hidden... (its weight is based on the pavilion side of the stone.)
It does not add to the beauty!!!
Versus other fancy cuts that enjoy a substantial % of weight on the crown!!! (a part of the stone that visualy sticks out of the jewelry and is considered a sought after look.)
 

Paul-Antwerp

Ideal_Rock
Trade
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Sep 2, 2002
Messages
2,852
Diagem,

In a princess-cut, there is no relation between depth and spread. It is technically very easy to hide weight, both in the pavilion as in the crown area, without increasing the depth, even while cutting with a very shallow depth.

In fact, princess-cuts need a depth, which looks relatively high, in order to improve light performance. Hence, you will have the impression that AGS-princesses all have high depths. This does not mean that their spread is less.

In this article, I explain that a depth of over 70% in a fancy shape is only psychologically high, because depth is measured in a different way than in rounds: article 1

In this article, you will find a first explanation on how two independent angles (in crown or in pavilion) can hide weight while not affecting depth: article 2

In this article, I show how notation and psychology play a role in measurements of square-cuts: article 3

And if you do a search here on my posts, which relate to depth in a princess-cut, you will find countless examples, why there is no relationship between depth and spread.

Live long,
 

oldminer

Ideal_Rock
Trade
Joined
Sep 3, 2000
Messages
6,378
Paul is ahead of the industry in this revelation, but he is correct. We are working on making the grading of SPREAD mean something more than a relationship to depth percentage. He has shown this is not a parameter of great meaning any longer when it comes to princess cuts and probably for many other cuts, too.

For certain, the square area enclosed within the perimeter of the girdle of two diamonds of similar weight can be compared and one will absolutely know if one is larger in appearance, spreadier, than the other by using simple math. The question is if one diamond is worth more than another based on spread differences is interesting, but not one that can just be answered based on square area.....Sorry.
 

JulieN

Super_Ideal_Rock
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Jul 25, 2005
Messages
13,324
Date: 1/3/2007 4:37:29 PM
Author: DiaGem
By the way..., how deep can a princess go, and still be considered a 'top' AGS-0 cut???
76 seems to be the tipping point. most 77, 78 AGS reports I've seen get dinged on proportions, though may still get 0 grade for light performance.

In the PS tutorial, says that AGS 0 princess must no smaller than 75% of same carat Tolkowsky.
 

diagem

Ideal_Rock
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Date: 1/4/2007 12:55:07 PM
Author: Paul-Antwerp
Diagem,

In a princess-cut, there is no relation between depth and spread. It is technically very easy to hide weight, both in the pavilion as in the crown area, without increasing the depth, even while cutting with a very shallow depth. True, using split facets techniques will help hide weight and keep TD% down.

In fact, princess-cuts need a depth, which looks relatively high, in order to improve light performance. Hence, you will have the impression that AGS-princesses all have high depths. This does not mean that their spread is less. Sorry, but i have seen amazing 6.5mm princesses at 6/4 grainers. And they were based on the low 60%''s depth %''s. I have no idea how they would judge up to AGS standards, but to my eyes they pass all tests.

In this article, I explain that a depth of over 70% in a fancy shape is only psychologically high, because depth is measured in a different way than in rounds: article 1 I agree, i wrote in prior posts that you cant judge ANY fancy shapes with the laws of Brilliant Rounds.

In this article, you will find a first explanation on how two independent angles (in crown or in pavilion) can hide weight while not affecting depth: article 2
see my first comment...

In this article, I show how notation and psychology play a role in measurements of square-cuts: article 3


And if you do a search here on my posts, which relate to depth in a princess-cut, you will find countless examples, why there is no relationship between depth and spread. i hope that we can agree that a 5.3mm 4 grainer will have a different face up appearance than a 6.0mm 4 grainer...

Live long,
Again, like i posted before, since the division between the crown and pavilion depth is not much of an issue... (princess cuts usually have shallow crowns heights and deep pavilions), they play by different laws of optics when comparing to other fancy shapes that can enjoy the effects from a relatively high crown height/depth.

In princess cuts, the weight of the stone is hidden mostly on the 1st. pavilion unlike other fancy shapes that can enjoy a visually high crown angle and height.
 
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