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I need some advice with this diamond. Comments??

flyingpig

Ideal_Rock
Premium
Joined
Nov 7, 2015
Messages
2,547
too deep at 62.7 (looks smaller than it should)
crown is too steep at 36.5 (you want 34~35, maybe 35.5, maybe 36 with that pav angle of 40.6, but not 36.5)
keep looking
 

cramir

Rough_Rock
Joined
Mar 13, 2016
Messages
19
When I mention the steep angle he said the following:

"But with a Star length of 50% and Table of 56% this is exactly the angle you need. You need to factor in the whole picture. Also, that’s why it gets an excellent luster grade - highest you can get. They are both cut far better than the others you showed me. Do you want a smaller star length and narrower angles? That also makes the diamond look smaller and you don’t gain any brilliance…"
 

flyingpig

Ideal_Rock
Premium
Joined
Nov 7, 2015
Messages
2,547
cramir|1457929502|4004845 said:
When I mention the steep angle he said the following:

"But with a Star length of 50% and Table of 56% this is exactly the angle you need. You need to factor in the whole picture. Also, that’s why it gets an excellent luster grade - highest you can get. They are both cut far better than the others you showed me. Do you want a smaller star length and narrower angles? That also makes the diamond look smaller and you don’t gain any brilliance…"
Run from this vendor, unless you actually saw the stone in person, and liked it. That's a different story.

But the numbers alone, it is less than ideal. It is less than spectacular for sure.

Have you checked HCA score??
https://www.pricescope.com/tools/hca
You want a score less than 2.0. This one is 2.4.

Sure, it is GIA Excellent. But, it just barely makes it.
http://www.diamondcut.gia.edu/pdfs/booklet_cut_estimation_tables_lowres.pdf

It can be decent like this. Need idealscope image
http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-3571556.htm
Regardless, it is too deep at 62.7% depth. Still, not most ideal. It also depends on the price.


I agree that "you need to factor in the whole picture".
 

Gypsy

Super_Ideal_Rock
Joined
Aug 8, 2005
Messages
40,198
The entire purpose of faceting a diamond is to reflect light.
How well or how poorly a diamond does this determines how beautiful it is.
How well a diamond performs is determined by the angles and cutting. This is why we say cut is king.
No other factor: not color, not clarity has as much of an impact on the appearance of a diamond as its cut. An ideal H will out white a poorly cut F. With round diamonds even a GIA triple Excellent is not enough. And you must stick to GIA and AGS only (HPD in Europe is good as well). EGL is a bad option: [URL='https://www.pricescope.com/community/threads/egl-certification-are-any-of-them-ok.142863/']https://www.pricescope.com/community/threads/egl-certification-are-any-of-them-ok.142863/[/URL]
So how to we ensure that we have the right angles and cutting to get the light performance we want?
https://www.pricescope.com/wiki/diamonds/diamond-cut
Well one method is to start with a GIA Ex, and then apply the HCA to it. YOU DO NOT USE HCA for AGS0 stones generally, though you can. In general, AGS0 trumps HCA though as one examines the actual stone and the other does not.
https://www.pricescope.com/wiki/diamonds/holloway-cut-advisor
The HCA is a rejection tool. Not a selection tool. It uses 4 data points to make a rudimentary call on how the diamond may perform.
If the diamond passes then you know that you are in the right zone in terms of angles for light performance. Under 2 is a pass. Under 2.5-2.1 is a maybe. 2.6 and over is a no. No score 2 and under is better than any other.
Is that enough? No, the HCA by itself is not enough.

So what you need is a way to check actual light performance of your actual stone.
That's what an idealscope image does. https://www.pricescope.com/wiki/diamonds/firescope-idealscope
It shows you how and wear your diamond is reflecting light, how well it is going at it, and where you are losing light return. That is why you won't see us recommending Blue Nile, as they do not provide idealscope images for their diamonds. BGD,BE, James Allen, GOG, HPD, ERD and WF do.

The Idealscope is the 'selection tool'. Not the HCA.
So yes, with a GIA stone you need the idealscope images. Or you can buy an idealscope yourself and take it in to the jeweler you are working with to check the stones yourself. Or if you have a good return policy (full refund minimum 7 days) then you can buy the idealscope, buy the stone, and do it at home.

Now if you want to skip all that... stick to AGS0 stones and then all you have to do is pick color and clarity and you know you have a great performing diamond. Because AGS has already done the checking for you. That's why they trade at a premium. Some AGS0's are better than others though, so pay attention to any ASET or IS provided.

In general with rounds, you will want a table 60% or less. A depth between 59 and 62.3. Crown angle 33.5-35 ( up to 36 okay if you can get an idealscope image). Pavilion Angle: 40.6-40.8 (there is a little give on this, you can go to 41 with an idealscope). And the crown and pavilion angles must be complimentary which is what the HCA checks for you.
 

Dancing Fire

Super_Ideal_Rock
Premium
Joined
Apr 3, 2004
Messages
32,445
cramir|1457941083|4004950 said:
How about Luster been excellent as well as H&A.
post a pic of the hearts.
 

flyingpig

Ideal_Rock
Premium
Joined
Nov 7, 2015
Messages
2,547
cramir|1457941083|4004950 said:
How about Luster been excellent as well as H&A.
I don't know what excellent luster grade is, mentioned by the vendor.
GIA grades color, clarity, polish, symmetry, and cut. Luster is a term used by GIA to describe polish grade, which is not affected as long as polish grade is very good or excellent.
If I were you, I won't engage with this vendor any further. This vendor already lost my respect (when he said 36.5 crown EXACTLY you want) and does not deserve $15k.

I won't go into detail (eg star, H&A, brilliance, etc...). There is no point.
 

RockBrat

Shiny_Rock
Joined
Feb 22, 2016
Messages
116
While this diamond does fall outside of what many members of this forum consider to be ideal, there are many beautiful diamonds that are graded excellent by GIA that are overlooked because they are not considered here to be super ideal. The vendor is correct that you do have to look at the big picture and how all the numbers work together as a whole. I have seen many diamonds that score very well on the HCA that have ideal proportions and are real dogs in person. Donuts of light leakage, and other problems. I have seen diamonds in person that fall outside of the ideal parameters recommended here that are amazing diamonds. The proportions recommended here are good guidelines but just because something falls outside of them doesn't mean it is not beautiful. If you want a super ideal performer based on paper, then it's best to follow guidelines recommended here. However, I saw a diamond recently with similar proportions to the one you're considering and it was one of the most beautiful diamonds I've ever seen. As the proportions weren't an exact match to yours I do not know what yours would look like in person or how it would perform or what issues it may have. What I can tell you is it would most likely have large but short bold flashes of fire around its surface similar to an OEC. I say most likely because I cannot see it in person but if someone were to find a diamond of similar proportions that truly was an excellent cut diamond and didn't have any light leak issues, that's the affect of fire you'd get.
 

tyty333

Super_Ideal_Rock
Premium
Joined
Dec 17, 2008
Messages
22,685
Get an aset or an idealscope image. Get H&A image to prove H&A.
 

cramir

Rough_Rock
Joined
Mar 13, 2016
Messages
19
Thank you everyone for all your insights. I will take a look at the stone and decide. I will run a couple of tests as well once I have it in my hands.

Cheers
 

gr8leo87

Shiny_Rock
Joined
Apr 24, 2015
Messages
381
cramir said:
When I mention the steep angle he said the following:

"But with a Star length of 50% and Table of 56% this is exactly the angle you need. You need to factor in the whole picture. Also, that’s why it gets an excellent luster grade - highest you can get. They are both cut far better than the others you showed me. Do you want a smaller star length and narrower angles? That also makes the diamond look smaller and you don’t gain any brilliance…"
Rubbish.

Nuff said.
 

gr8leo87

Shiny_Rock
Joined
Apr 24, 2015
Messages
381
cramir said:
How about Luster been excellent as well as H&A.
The luster being excellent (as mentioned on trade networks) means the diamond has full transparency - not hazy or milky.

It has nothing to do with performance of the diamond.
 

MissGotRocks

Super_Ideal_Rock
Premium
Joined
Jun 23, 2005
Messages
12,722
RockBrat|1457961936|4005026 said:
While this diamond does fall outside of what many members of this forum consider to be ideal, there are many beautiful diamonds that are graded excellent by GIA that are overlooked because they are not considered here to be super ideal. The vendor is correct that you do have to look at the big picture and how all the numbers work together as a whole. I have seen many diamonds that score very well on the HCA that have ideal proportions and are real dogs in person. Donuts of light leakage, and other problems. I have seen diamonds in person that fall outside of the ideal parameters recommended here that are amazing diamonds. The proportions recommended here are good guidelines but just because something falls outside of them doesn't mean it is not beautiful. If you want a super ideal performer based on paper, then it's best to follow guidelines recommended here. However, I saw a diamond recently with similar proportions to the one you're considering and it was one of the most beautiful diamonds I've ever seen. As the proportions weren't an exact match to yours I do not know what yours would look like in person or how it would perform or what issues it may have. What I can tell you is it would most likely have large but short bold flashes of fire around its surface similar to an OEC. I say most likely because I cannot see it in person but if someone were to find a diamond of similar proportions that truly was an excellent cut diamond and didn't have any light leak issues, that's the affect of fire you'd get.

I am curious as to where you have seen these stones? Are you a vendor or just an avid diamond shopper?
 

RockBrat

Shiny_Rock
Joined
Feb 22, 2016
Messages
116
MissGotRocks|1458081987|4005849 said:
RockBrat|1457961936|4005026 said:
While this diamond does fall outside of what many members of this forum consider to be ideal, there are many beautiful diamonds that are graded excellent by GIA that are overlooked because they are not considered here to be super ideal. The vendor is correct that you do have to look at the big picture and how all the numbers work together as a whole. I have seen many diamonds that score very well on the HCA that have ideal proportions and are real dogs in person. Donuts of light leakage, and other problems. I have seen diamonds in person that fall outside of the ideal parameters recommended here that are amazing diamonds. The proportions recommended here are good guidelines but just because something falls outside of them doesn't mean it is not beautiful. If you want a super ideal performer based on paper, then it's best to follow guidelines recommended here. However, I saw a diamond recently with similar proportions to the one you're considering and it was one of the most beautiful diamonds I've ever seen. As the proportions weren't an exact match to yours I do not know what yours would look like in person or how it would perform or what issues it may have. What I can tell you is it would most likely have large but short bold flashes of fire around its surface similar to an OEC. I say most likely because I cannot see it in person but if someone were to find a diamond of similar proportions that truly was an excellent cut diamond and didn't have any light leak issues, that's the affect of fire you'd get.

I am curious as to where you have seen these stones? Are you a vendor or just an avid diamond shopper?
I am not a vendor, I am just an avid diamond looker lol. I used the HCA for my own experience in swapping out the diamond from my engagement ring, which I've done 4 times now. I've never found my "just right." The HCA is a great tool and I use it to analyze many things but I have been disappointed in how it translated to the diamonds I've seen in real life. I think if it is used in conjunction with the vendors recommended here it is much more successful because unfortunately in what I saw, the other factors not accounted for made too much of a difference.
 

MissGotRocks

Super_Ideal_Rock
Premium
Joined
Jun 23, 2005
Messages
12,722
RockBrat|1458088905|4005893 said:
MissGotRocks|1458081987|4005849 said:
RockBrat|1457961936|4005026 said:
While this diamond does fall outside of what many members of this forum consider to be ideal, there are many beautiful diamonds that are graded excellent by GIA that are overlooked because they are not considered here to be super ideal. The vendor is correct that you do have to look at the big picture and how all the numbers work together as a whole. I have seen many diamonds that score very well on the HCA that have ideal proportions and are real dogs in person. Donuts of light leakage, and other problems. I have seen diamonds in person that fall outside of the ideal parameters recommended here that are amazing diamonds. The proportions recommended here are good guidelines but just because something falls outside of them doesn't mean it is not beautiful. If you want a super ideal performer based on paper, then it's best to follow guidelines recommended here. However, I saw a diamond recently with similar proportions to the one you're considering and it was one of the most beautiful diamonds I've ever seen. As the proportions weren't an exact match to yours I do not know what yours would look like in person or how it would perform or what issues it may have. What I can tell you is it would most likely have large but short bold flashes of fire around its surface similar to an OEC. I say most likely because I cannot see it in person but if someone were to find a diamond of similar proportions that truly was an excellent cut diamond and didn't have any light leak issues, that's the affect of fire you'd get.

I am curious as to where you have seen these stones? Are you a vendor or just an avid diamond shopper?
I am not a vendor, I am just an avid diamond looker lol. I used the HCA for my own experience in swapping out the diamond from my engagement ring, which I've done 4 times now. I've never found my "just right." The HCA is a great tool and I use it to analyze many things but I have been disappointed in how it translated to the diamonds I've seen in real life. I think if it is used in conjunction with the vendors recommended here it is much more successful because unfortunately in what I saw, the other factors not accounted for made too much of a difference.
Interesting perspective. I've actually had just the opposite experience so I was wondering how this worked for you. Thanks for your input!
 

gr8leo87

Shiny_Rock
Joined
Apr 24, 2015
Messages
381
MissGotRocks said:
RockBrat|1458088905|4005893 said:
MissGotRocks|1458081987|4005849 said:
RockBrat|1457961936|4005026 said:
While this diamond does fall outside of what many members of this forum consider to be ideal, there are many beautiful diamonds that are graded excellent by GIA that are overlooked because they are not considered here to be super ideal. The vendor is correct that you do have to look at the big picture and how all the numbers work together as a whole. I have seen many diamonds that score very well on the HCA that have ideal proportions and are real dogs in person. Donuts of light leakage, and other problems. I have seen diamonds in person that fall outside of the ideal parameters recommended here that are amazing diamonds. The proportions recommended here are good guidelines but just because something falls outside of them doesn't mean it is not beautiful. If you want a super ideal performer based on paper, then it's best to follow guidelines recommended here. However, I saw a diamond recently with similar proportions to the one you're considering and it was one of the most beautiful diamonds I've ever seen. As the proportions weren't an exact match to yours I do not know what yours would look like in person or how it would perform or what issues it may have. What I can tell you is it would most likely have large but short bold flashes of fire around its surface similar to an OEC. I say most likely because I cannot see it in person but if someone were to find a diamond of similar proportions that truly was an excellent cut diamond and didn't have any light leak issues, that's the affect of fire you'd get.

I am curious as to where you have seen these stones? Are you a vendor or just an avid diamond shopper?
I am not a vendor, I am just an avid diamond looker lol. I used the HCA for my own experience in swapping out the diamond from my engagement ring, which I've done 4 times now. I've never found my "just right." The HCA is a great tool and I use it to analyze many things but I have been disappointed in how it translated to the diamonds I've seen in real life. I think if it is used in conjunction with the vendors recommended here it is much more successful because unfortunately in what I saw, the other factors not accounted for made too much of a difference.
Interesting perspective. I've actually had just the opposite experience so I was wondering how this worked for you. Thanks for your input!
HCA has it's own weaknesses. Many stones with hca under 2 can be dogs IRL. Specially according to PS preferences.

It arbitrarily (atleast appears to) compensate shallow crown by deeper pavillions and vice versa. The only two other proportions it takes into account is table and depth. For any depth deeper than 60.4 (or 60.2) it doesn't give excellent spread.

Most diamonds recommended on this forum don't get EX for spread. I have also seen diamonds with beautiful light return according to their ASETs and they score above 2 on HCA.
 
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