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Is this diamond to deep?

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TuffEnough

Rough_Rock
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Hi everyone-

Would like to get a quick opinion on this diamond, I''m concerned that it may be a little deep and the spread a little small compared to other diamonds the same size. Please let me know what your opinion is.

Round Brilliant
2.51 carat
8.63 x 8.68 x 5.47
Depth - 63.2
Table - 56%
Girdle - thin to slgt thick
cutlet - none
Polish - Vg
Symmetry - VG
Clarity - SI1
Color - J
Flourescence - none

This has a GIA cert - the older one so there are no crown or pavillion angles present.
 

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JulieN

Super_Ideal_Rock
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since crown/pav not known, best to err on safe side.
 

belle

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yeah, it's getting up there with the depth. it might not only look smaller but the depth is going to emphasize the 'j' color more as well.
of course if carat weight is most important and you are getting a great price, it might be worth considering.

depth and lack of the all important c/p angles would cause me to skip it but it really depends on what *you* are looking for.
 

Garry H (Cut Nut)

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Date: 1/4/2007 12:19:04 AM
Author: Second City
What is the certificate''s date? If it is on or after January 1, 2005, you can look up the other information using the following link:

http://www.gia.edu/reportcheck/
Some quite older reports can be listed there.

But i doubt it will have good proportions
 

TuffEnough

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Thanks for the input....I went to the GIA link provided and it does have the diamond listed but does not have any additional proportions (crown, pavillion, etc) listed. Is it possible for this to be a good diamond? Just wondering, as I put a deposit down on it but can still change my mind.
 

JulieN

Super_Ideal_Rock
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possible, but unlikely.

buy an Ideal Scope.

even if well proportioned, probably not the best proportions for 2.5 ct J.
 

JulieN

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Date: 1/4/2007 1:14:13 AM
Author: DBM
sometimes added depth helps the face up color, keep in mind especially with the J.
explain this, please
 

DBM

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Date: 1/4/2007 1:14:46 AM
Author: JulieN

Date: 1/4/2007 1:14:13 AM
Author: DBM
sometimes added depth helps the face up color, keep in mind especially with the J.
explain this, please
a deep stone can help the color of a stone face up and since she has a J color it could be that the added depth on the stone is actually helping the ultimate look. Were it to be more shallower you might see more of the yellow face up, and it''s a J so it''s something to consider.
 

JulieN

Super_Ideal_Rock
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shallow crown/steeper pav combos return more white light, improving face up color.
 

DBM

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Date: 1/4/2007 4:19:37 AM
Author: JulieN
shallow crown/steeper pav combos return more white light, improving face up color.
in all honesty i don''t know much about the metrics of it to say you''re right or wrong but i know what i know from experience and deep stones can make the stone''s color harder to see face up. that''s just my empirical experience. i don''t know how to prove it or explain it...

also though i think we''re talking about apples and oranges. you''re talking in terms of optimizing the reflection of light but that''s not IMO a component of color. An ideal cut of a J let''s say with optimum physical light reflection does NOT in truth make the face up of the diamond an I.. i''m sure there''s a whole ton of threads on this isolating the various components of light, scintillation, etc, colorimeter, etc but again all i can say is from experience is that every diamond, even ideal, has bright spots and dark spots -- the color can be seen in the dark spots. In other words an ideal cut J seen by a gemologist can still be identified as a J face up.
 

strmrdr

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Date: 1/4/2007 4:34:41 AM
Author: DBM

Date: 1/4/2007 4:19:37 AM
Author: JulieN
shallow crown/steeper pav combos return more white light, improving face up color.
in all honesty i don''t know much about the metrics of it to say you''re right or wrong but i know what i know from experience and deep stones can make the stone''s color harder to see face up. that''s just my empirical experience. i don''t know how to prove it or explain it...
With back lighting yep but put the same stone in a bezel or tight setting or let it get a bit dirty and that will change in a hurry.
Those familiar with Jon''s lighting video think of the dealer lighting with light background and say ahah :}

I dont agree much with your other comment but my arm wont hold up to getting in too it. So it will have to wait until another day :}
 

strmrdr

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Date: 1/4/2007 4:34:41 AM
Author: DBM

also though i think we're talking about apples and oranges. you're talking in terms of optimizing the reflection of light but that's not IMO a component of color. An ideal cut of a J let's say with optimum physical light reflection does NOT in truth make the face up of the diamond an I.. i'm sure there's a whole ton of threads on this isolating the various components of light, scintillation, etc, colorimeter, etc but again all i can say is from experience is that every diamond, even ideal, has bright spots and dark spots -- the color can be seen in the dark spots. In other words an ideal cut J seen by a gemologist can still be identified as a J face up.
shoot going to go for broke here cuz I can take more meds in 30 min.
Im going to get yelled at for getting into diamond 801 in a 101 forum but oh well :}

There are many different issues when talking about diamond color.
The labs grade material color where face up color is apparant color and apparant material color which is not the same as material color and not the same as each other. Then you have enviremental, reflected and refracted color which are also different.

Cut can improve or make worse the apparant color and the apparant material color of a diamond but not the material color.
Even size doesnt change the lab material color but the apparant material color changes as the stone size changes.
Remember that lab diamond color is if you took a slice of the diamond and looked thru it and it starts to make sence.
 

strmrdr

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btw saying a lab J colored diamond is an I face up without specifing which color is being discussed and that they are not the same thing is near fraud and far too common.
 

Garry H (Cut Nut)

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DBM I must weigh in here and support Storm

the brightest highest light return cuts with the shortest ray paths and the most extinction and contrast (shallower rounds - not deeper) reduce the face up color of diamonds.

The cuts like radiant that reduce the color (or make light colored material into fancy colors) are the exact opposite of what I described above.

Only 1 lab to my knowledge considers the face up color of colorless graded diamonds. IGI do a face up test on border line stones - and this is one reason why some people think they are soft on color - because we see more well cut rounds bumped up 1/2 a grade. It actually makes sense I think and I commend them for it because they would stop people being disappointed with H - k colored radiants, ovals, pear shapes etc
 

diagem

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Very simple...

The shalower the diamond, the less color is kept in its body!!!
The heavier the diamond, the more color is kept in!

See Garry''s example on fancy colors...

Most fancy colored diamonds are cut on the heavy side to keep as much color as possible.
Thats why when you are "lucky" to find a beautifully made fancy shaped, fancy color diamond with facets and angle that are normaly cut on colorless diamonds, you will pay a heavy premium for them...
 

DBM

Shiny_Rock
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can''t type too much at the moment. it is certainly intuitive what DiaGem mentioned that the deeper the stone is the more material there is "concentrated" in one place and hence easier to see.. i don''t know.. I''ll have to re-examine again.. maybe the stones i see are not evenly distributed hues througout. will get back.
also would like to ask the opinion of some cutters here in the district and get back on this.
 

JohnQuixote

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DiaGem is right on. Diamonds in the D-Z range are color-graded upside down, viewed from the side, largely because a diamond's cut proportions may result in the entrapment of more color (steep or very shallow combos)...or less color (when cut for optimum light return).

When a diamond is cut so that almost all light entering the crown reflects from the pavilion at precise angles back to the viewer’s eyes it entraps less body color and will have increased brilliance, dispersion and scintillation.This is most observable in premium rounds because their circular shape and brilliant faceting style maximize light return and performance qualities.As mentioned, rounds in the top few percent of the world’s cut quality often appear more colorless face-up than their lab-assigned grade thanks to the optimum light return.

Unlike diamonds on the D-Z scale, fancy colored stones are graded face-up, judging hue, tone and saturation. Such stones are cut to ENTRAP as much body color as possible, which is why many are cut in square shapes.Fancy colored round diamonds typically have proportion sets steeper or shallower than commonly agreed on ‘ideal’ proportions.This causes light to pass through the stone, nicely illuminating the color but not washing it out.

Diamond cutters committed to optimum face-up appearance typically caution against steep/deep combinations in D-Z shapes: In addition to appearing smaller for their weight, such proportions sets entrap body color more readily.

The work of Basil Watermeyer, Henry Grossbard & contemporaries, and the development of the Barion, Radiant and similar cuts is good reference material on this subject.
 

Regular Guy

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Date: 1/4/2007 1:04:37 PM
Author: JohnQuixote
DiaGem is right on.
Sorry, DiaGem may be right on, but mostly DiaGem is AWOL.

Report in!

Sorry to interrupt.
 

aljdewey

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Date: 1/3/2007 11:17:16 PM
Author:TuffEnough

Would like to get a quick opinion on this diamond, I''m concerned that it may be a little deep and the spread a little small compared to other diamonds the same size. Please let me know what your opinion is.

This has a GIA cert - the older one so there are no crown or pavillion angles present.
My opinion is that there are better choices out there, so I''d likely not select a diamond with this depth.

You can ask for a Sarin report for stones that are older and don''t reflect crown/pavilion angle info on the grading report. This is what has historically been used previously.
 

DBM

Shiny_Rock
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Messages
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ok so i haven''t had a chance to ask enough cutters as i would like yet but so far of the two cutters (one''s a former cutter though) i''ve asked one said shallow stones give whiter appearance face up and one says (the former cutter) the other way, that the depth of the a stone helps the face-up color/look. It''s still on my mind.
 

Garry H (Cut Nut)

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Date: 1/10/2007 6:04:34 PM
Author: DBM
ok so i haven''t had a chance to ask enough cutters as i would like yet but so far of the two cutters (one''s a former cutter though) i''ve asked one said shallow stones give whiter appearance face up and one says (the former cutter) the other way, that the depth of the a stone helps the face-up color/look. It''s still on my mind.
Daniel it is way more complex than that.
I suggest you read this article and then teach all yoour cutters and pro''s about the issue so we all stop with the old wives tales.
Gems & Gemology Summer 2006

round v s radiant color x_edited-1.jpg
 

Garry H (Cut Nut)

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Date: 1/4/2007 7:30:46 AM
Author: Garry H (Cut Nut)
DBM I must weigh in here and support Storm

the brightest highest light return cuts with the shortest ray paths and the most extinction and contrast (shallower rounds - not deeper) reduce the face up color of diamonds.

The cuts like radiant that reduce the color (or make light colored material into fancy colors) are the exact opposite of what I described above.

Only 1 lab to my knowledge considers the face up color of colorless graded diamonds. IGI do a face up test on border line stones - and this is one reason why some people think they are soft on color - because we see more well cut rounds bumped up 1/2 a grade. It actually makes sense I think and I commend them for it because they would stop people being disappointed with H - k colored radiants, ovals, pear shapes etc
Daniel I hope this helps too.
And please re-read my earlier post.

The thing is the cutters who really know how to play with color, well, they will have to kill you if they told you anything helpful


Bad round good color.JPG
 

DBM

Shiny_Rock
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Messages
404
so far all i'm getting is that a radiant cut creates more color.

Where do we see about addiing to depth a round stone adding more color?

i honestly don't know what you mean by shortest ray path and highest light return in regard to deepening of a stone... i guess i'll have to get a copy of the gems and gemology 2006 edition before we can discuss anything further. thx!
 

Garry H (Cut Nut)

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Date: 1/10/2007 6:30:56 PM
Author: DBM
so far all i''m getting is that a radiant cut creates more color.

Where do we see about addiing to depth a round stone adding more color?

i honestly don''t know what you mean by shortest ray path and highest light return in regard to deepening of a stone... i guess i''ll have to get a copy of the gems and gemology 2006 edition before we can discuss anything further. thx!
Daniel I am not your teacher


Please read the article I mentioned if it is something you wish to know about.
The radiant is in fact likely to be deeper now than the round beause they made it narrower!

But it is not as simple as shallow or deep.
The second photo I posted - you may not have seen - also shows that poor symmetry can make color improve (or get lower in D-Z) because it makes the light stay longer in the diamond - stops the in and out John has been trying to explain.
 

DBM

Shiny_Rock
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Messages
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i'm not looking to bother you about this... i'm not fully sure i understand what position you're taking though. It sounds like you're saying "it can depend and vary. Sometimes depth can make it whiter, sometimes, yellower, sometimes off symmetry can make it better sometimes off-symmetry can make it worse.." did i get the gist of it?

the only point i was trying to say in all this was that the added depth can help a J colored diamond (which in my opinion is a little risky to be put into a white metal) look better than usual... is that something you agree or disagree with? or feel no comment can be made on?
 

strmrdr

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I'm going to try and make this as simple as possible.

The more material the light travels thru the more color it picks up.
This is bad for D-Z but good for fancy colored diamonds.

Well cut, shallowish, optically symmetrical stones have the shortest light path.
That means the light spends the least amount of time and distance in them.
A radiant has a long light path with the light bouncing around many times so is a good choice to bring out the apparent color in fancy colored rough.

A too deep diamond is the opposite of what you want in a J.
A shallower stone will face up whiter in apparent color. (complicated by: until you get too shallow and head shadow is a problem or light return drops off)

edit: assuming equal optical symmetry because it is another variable that can change the results and make the deeper stone appear lighter in apparent color.
 

strmrdr

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To show it in simple terms find a see thru but tinted material look thru one layer then 2 layers of the material.
2 layers will show more color because the light is traveling thru more material.

1 layer is better if the goal is light apparent color (D-Z)
2 layers is better if deeper apparent color and graded color is wanted (Fancy Colored, graded face up so apparent color and graded color are the same)
 

JohnQuixote

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Date: 1/10/2007 6:50:45 PM
Author: DBM
i'm not looking to bother you about this... i'm not fully sure i understand what position you're taking though. It sounds like you're saying 'it can depend and vary. Sometimes depth can make it whiter, sometimes, yellower, sometimes off symmetry can make it better sometimes off-symmetry can make it worse..' did i get the gist of it?

the only point i was trying to say in all this was that the added depth can help a J colored diamond (which in my opinion is a little risky to be put into a white metal) look better than usual... is that something you agree or disagree with? or feel no comment can be made on?
Daniel, it's no bother here.
We enjoy discussion and this is a subject with great complexity.

With specific regard to a J colored round brilliant; added depth will not help it appear more colorless. This from Brian Gavin, who has cut diamonds for a long time:

"Steep/deep cutting entraps body color. We all know that well-cut diamonds show less color face-up due to optimized light return. Alternately, steep/deep cutting entraps body color (fancy colored rounds are cut either very shallow or steep precisely because of this). At combinations near 41.8 / 34.X the diamond appears darker and the color becomes more apparent in the face up position. Put a 41.8 angle on a J color and see how yellow it looks. This is the opposite of masking color with great cut... ...Additionally, steep/deep cutting hides weight. As the pavilion is made steeper spread is reduced. A 41.8 pavilion can add nearly 4% weight to the bottom of a stone without improving spread."

The "in and out" Garry alluded to is what Strm explained.

In scientific terms it has to do with efficiency of the light return. If light enters the crown and is returned after a short trip with intensity to the viewer's eye you will see less of the stone's color. Top crown/pavilion angles get the light in and out of the stone faster, as does optical symmetry. Alternately, at steep/deep angles, the light remains in the stone longer and some of it is escaping from the diamond's pavilion, so light return is decreased (see graphics below). Both of these factors contribute to more color apparent in the stone.

Here are sims of 3 diamonds of increasing depth. These models assume perfect optical symmetry. Note the decrease in light return values (and mm spread for carat weight too - not a light return concern but one of size appearance).

LR609Example1.jpg
 
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