help with GIA 3ex stone..is this a bad steep deep?

[mermi2015]

Found this stone on jamesallen.com. I like the price and the size but the 36/40.8 with lgf% 75 makes me hesitant to buy. Plus it has hca score of 3.7. Looking at the video I don't see any obvious leakage. Then again I am new to steep deep stone, not too sure what I am suppose to be looking for. I have asked for an ASET image but I was told it is not available.

Here are the specs:
https://www.jamesallen.com/loose-diamonds/round-cut/1.36-carat-m-color-si1-clarity-excellent-cut-sku-2404538

depth: 62.1
table: 57
crown angle: 36
crown %: 15.5
pavilion angle: 40.8
pavilion%: 43
girdle: medium
lgf%: 75


can anyone with trained eyes please take a look at the video clip. I would greatly appreciated if you could tell the negative affects of steep deep on this stone. Thank you very very much!

 

[Lore]

The poor HCA score should be an indication to stay away. I'd start by finding diamonds with a score under 2.0 and then filter from that based on your requirements for carat, color, and clarity.

You can't see leakage by looking at the video, so ask for an Ideascope image of the diamond instead and compare against this http://ideal-scope.com/reference-chart-ideal-scope-images/.. If you see a ring of white/gray under the table then you have some leakage.

Take a look at this table too for some guidance on what angles and percentages makes a super ideal cut!
https://www.pricescope.com/wiki/diamonds/diamond-grading-chart-round

 

[mermi2015]

The poor HCA score should be an indication to stay away. I'd start by finding diamonds with a score under 2.0 and then filter from that based on your requirements for carat, color, and clarity.

You can't see leakage by looking at the video, so ask for an Ideascope image of the diamond instead and compare against this http://ideal-scope.com/reference-chart-ideal-scope-images/... If you see a ring of white/gray under the table then you have some leakage.

Take a look at this table too for some guidance on what angles and percentages makes a super ideal cut!
https://www.pricescope.com/wiki/diamonds/diamond-grading-chart-round

thanks for your advice. that seems to be the standard procedure. I did start my search that way until I stumbled on this one. the only reason I am considering this stone is because I own a 35.5/40.6 lgf 80% diamond. absolutely love this stone, sparkles magnificently . the crown and the pavilion on this 1.36 ct seems just so slightly steeper with shorter lgf. Though that difference of 5% in lgf probably isn't really 5% given how GIA rounds it measurements. My question is, visually will this difference be noticeable to untrained eyes? thanks for your help!

 

[flyingpig]

if you could tell the negative affects of steep deep on this stone.

The washed out looking arrows and clearly visible yellow tint under the table due to light leakage.

Yes this will be noticeable.

 

[mermi2015]

if you could tell the negative affects of steep deep on this stone.

The washed out looking arrows and clearly visible yellow tint under the table due to light leakage.

Yes this will be noticeable.

Thanks for your help! Really enjoy learning these techniques from the pros here. Could you take a look at this diamond?

https://www.jamesallen.com/loose-diamonds/round-cut/1.06-carat-k-color-si2-clarity-excellent-cut-sku-2273053

I've also noticed the yellow tint under the table, not as much as the 1.36 ct. but the hca for this stone is 1.1.

 

[flyingpig]

if you could tell the negative affects of steep deep on this stone.

The washed out looking arrows and clearly visible yellow tint under the table due to light leakage.

Yes this will be noticeable.

Thanks for your help! Really enjoy learning these techniques from the pros here. Could you take a look at this diamond?

https://www.jamesallen.com/loose-diamonds/round-cut/1.06-carat-k-color-si2-clarity-excellent-cut-sku-2273053

I've also noticed the yellow tint under the table, not as much as the 1.36 ct. but the hca for this stone is 1.1.

Yes, this one shows less tint, partially because of higher color and partially because of less light leakage.

It is important to notice difference between yellow "tint" and yellow "reflection".

You see tint when there is light leakage (or no reflection). That's why tint is the most visible when viewed from the side. No reflection, therefore you see the body color or tint.

 

[gm89uk]

can anyone with trained eyes please take a look at the video clip. I would greatly appreciated if you could tell the negative affects of steep deep on this stone. Thank you very very much!

Just look at the appearance of the diamond under the table compared to the edge of the diamond, see how much darker it looks in the middle compared to the edge? There is a contrast in brightness in the head on view of edge of diamond compared to middle. This can signify a dulled diamond that appears lifeless in the middle due to leakage under the table (typical of steep deep diamonds)

By random I just found an ideal cut diamond
https://www.jamesallen.com/loose-diamonds/round-cut/0.72-carat-h-color-si2-clarity-excellent-cut-sku-2324230

look at the consistency of brightness between the edge and the middle (under the table), it is almost exactly the same intensity of bright white return.

Videos can vary and this isn't a reliable way to assess leakage, you need an idealscope/ASET for that, but it's some of the clues you can use.

This is a more extreme example to demonstrate what I mean:

https://www.jamesallen.com/loose-diamonds/round-cut/0.70-carat-l-color-vs1-clarity-excellent-cut-sku-2408010

 

[mermi2015]

can anyone with trained eyes please take a look at the video clip. I would greatly appreciated if you could tell the negative affects of steep deep on this stone. Thank you very very much!

Just look at the appearance of the diamond under the table compared to the edge of the diamond, see how much darker it looks in the middle compared to the edge? There is a contrast in brightness in the head on view of edge of diamond compared to middle. This can signify a dulled diamond that appears lifeless in the middle due to leakage under the table (typical of steep deep diamonds)

By random I just found an ideal cut diamond
https://www.jamesallen.com/loose-diamonds/round-cut/0.72-carat-h-color-si2-clarity-excellent-cut-sku-2324230

look at the consistency of brightness between the edge and the middle (under the table), it is almost exactly the same intensity of bright white return.

Videos can vary and this isn't a reliable way to assess leakage, you need an idealscope/ASET for that, but it's some of the clues you can use.

This is a more extreme example to demonstrate what I mean:

https://www.jamesallen.com/loose-diamonds/round-cut/0.70-carat-l-color-vs1-clarity-excellent-cut-sku-2408010

Thank you so much for the detailed explanation! the examples you gave really help visualize the idea!

 

[mermi2015]

if you could tell the negative affects of steep deep on this stone.

The washed out looking arrows and clearly visible yellow tint under the table due to light leakage.

Yes this will be noticeable.

Thanks for your help! Really enjoy learning these techniques from the pros here. Could you take a look at this diamond?

https://www.jamesallen.com/loose-diamonds/round-cut/1.06-carat-k-color-si2-clarity-excellent-cut-sku-2273053

I've also noticed the yellow tint under the table, not as much as the 1.36 ct. but the hca for this stone is 1.1.

Yes, this one shows less tint, partially because of higher color and partially because of less light leakage.

It is important to notice difference between yellow "tint" and yellow "reflection".

You see tint when there is light leakage (or no reflection). That's why tint is the most visible when viewed from the side. No reflection, therefore you see the body color or tint.

indeed. with more practice may be one day i'll be able to tell the difference

 

[bunnycat]

The poor HCA score should be an indication to stay away. I'd start by finding diamonds with a score under 2.0 and then filter from that based on your requirements for carat, color, and clarity.

You can't see leakage by looking at the video, so ask for an Ideascope image of the diamond instead and compare against this http://ideal-scope.com/reference-chart-ideal-scope-images/... If you see a ring of white/gray under the table then you have some leakage.

Take a look at this table too for some guidance on what angles and percentages makes a super ideal cut!
https://www.pricescope.com/wiki/diamonds/diamond-grading-chart-round

This one is also an IGI graded stone. I don't know much about what reliability IGI may or may not have in relation to GIA graded stones if you are trying to compare color.

Are you looking for a stone below I? There may be better places for you to search if so.

 

[bunnycat]

The poor HCA score should be an indication to stay away. I'd start by finding diamonds with a score under 2.0 and then filter from that based on your requirements for carat, color, and clarity.

You can't see leakage by looking at the video, so ask for an Ideascope image of the diamond instead and compare against this http://ideal-scope.com/reference-chart-ideal-scope-images/.... If you see a ring of white/gray under the table then you have some leakage.

Take a look at this table too for some guidance on what angles and percentages makes a super ideal cut!
https://www.pricescope.com/wiki/diamonds/diamond-grading-chart-round

thanks for your advice. that seems to be the standard procedure. I did start my search that way until I stumbled on this one. the only reason I am considering this stone is because I own a 35.5/40.6 lgf 80% diamond. absolutely love this stone, sparkles magnificently . the crown and the pavilion on this 1.36 ct seems just so slightly steeper with shorter lgf. Though that difference of 5% in lgf probably isn't really 5% given how GIA rounds it measurements. My question is, visually will this difference be noticeable to untrained eyes? thanks for your help!

35.5/40.6 can be a good match, and it sounds like you have one. I think you have to look at it on a stone by stone basis at that point as all the other supporting angles probably come in to play.

 

[mermi2015]

The poor HCA score should be an indication to stay away. I'd start by finding diamonds with a score under 2.0 and then filter from that based on your requirements for carat, color, and clarity.

You can't see leakage by looking at the video, so ask for an Ideascope image of the diamond instead and compare against this http://ideal-scope.com/reference-chart-ideal-scope-images/.... If you see a ring of white/gray under the table then you have some leakage.

Take a look at this table too for some guidance on what angles and percentages makes a super ideal cut!
https://www.pricescope.com/wiki/diamonds/diamond-grading-chart-round

This one is also an IGI graded stone. I don't know much about what reliability IGI may or may not have in relation to GIA graded stones if you are trying to compare color.

Are you looking for a stone below I? There may be better places for you to search if so.

Yes, I am. I bought a K not too long ago. its beautiful, and I don't mind the slight tint when looked at from the side. so I am open to lower colors. I have not seen a M in person though. I plan to have it set in 14 kt yellow gold bezel pendant. Hopefully the yellow tint is not that strong. what's a good place to search?

 

[bunnycat]

The poor HCA score should be an indication to stay away. I'd start by finding diamonds with a score under 2.0 and then filter from that based on your requirements for carat, color, and clarity.

You can't see leakage by looking at the video, so ask for an Ideascope image of the diamond instead and compare against this http://ideal-scope.com/reference-chart-ideal-scope-images/......... If you see a ring of white/gray under the table then you have some leakage.

Take a look at this table too for some guidance on what angles and percentages makes a super ideal cut!
https://www.pricescope.com/wiki/diamonds/diamond-grading-chart-round

This one is also an IGI graded stone. I don't know much about what reliability IGI may or may not have in relation to GIA graded stones if you are trying to compare color.

Are you looking for a stone below I? There may be better places for you to search if so.

Yes, I am. I bought a K not too long ago. its beautiful, and I don't mind the slight tint when looked at from the side. so I am open to lower colors. I have not seen a M in person though. I plan to have it set in 14 kt yellow gold bezel pendant. Hopefully the yellow tint is not that strong. what's a good place to search?

My suggestion is to look for something in the J/K range that has fluor. If you are looking to drop down to L/M, then Brian Gavin has a series cut specifically in the Cape colors. And in the J/K range I'd look in the Brian Gavin Blue line, which has fluor to help boost the face up color. No extra work or running number to be done, as they are all Ideal cut and all have light performance information added. You could also try Whiteflash, though they don't have specific series of stones like BG does so you'd have to weed through if you are looking for fluor, though they have their own specialty ideal cut as well. Sadly- I think inventory is low this close to V-day....

http://www.briangavindiamonds.com/diamonds/signature-diamonds/cape
http://www.whiteflash.com/

I don't know what size you are looking for, but here is a 1ct K at Whitflash:

http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-3738438.htm

and I considered this stone at BG and it was pretty, but we found one with fluor that was a little bigger and went with that (now in my avatar):

http://www.briangavindiamonds.com/diamonds/diamond-details/1.398-k-vs1-round-diamond-ags-104081043030

This one is pretty and a nice pendant size:
http://www.briangavindiamonds.com/diamonds/diamond-details/1.068-k-vs1-round-diamond-ags-104085572004

Good Old Gold also puts lots of performance metrics up so it's all there at a glance if you look there.


Alternatively, call Yekutiel at IDJ and let him work his magic. He's found fabulous stones for people and can do an idealscope as well.

 

[mermi2015]

The poor HCA score should be an indication to stay away. I'd start by finding diamonds with a score under 2.0 and then filter from that based on your requirements for carat, color, and clarity.

You can't see leakage by looking at the video, so ask for an Ideascope image of the diamond instead and compare against this http://ideal-scope.com/reference-chart-ideal-scope-images/.......... If you see a ring of white/gray under the table then you have some leakage.

Take a look at this table too for some guidance on what angles and percentages makes a super ideal cut!
https://www.pricescope.com/wiki/diamonds/diamond-grading-chart-round

This one is also an IGI graded stone. I don't know much about what reliability IGI may or may not have in relation to GIA graded stones if you are trying to compare color.

Are you looking for a stone below I? There may be better places for you to search if so.

Yes, I am. I bought a K not too long ago. its beautiful, and I don't mind the slight tint when looked at from the side. so I am open to lower colors. I have not seen a M in person though. I plan to have it set in 14 kt yellow gold bezel pendant. Hopefully the yellow tint is not that strong. what's a good place to search?

My suggestion is to look for something in the J/K range that has fluor. If you are looking to drop down to L/M, then Brian Gavin has a series cut specifically in the Cape colors. And in the J/K range I'd look in the Brian Gavin Blue line, which has fluor to help boost the face up color. No extra work or running number to be done, as they are all Ideal cut and all have light performance information added. You could also try Whiteflash, though they don't have specific series of stones like BG does so you'd have to weed through if you are looking for fluor, though they have their own specialty ideal cut as well. Sadly- I think inventory is low this close to V-day....

http://www.briangavindiamonds.com/diamonds/signature-diamonds/cape
http://www.whiteflash.com/

I don't know what size you are looking for, but here is a 1ct K at Whitflash:

http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-3738438.htm

and I considered this stone at BG and it was pretty, but we found one with fluor that was a little bigger and went with that (now in my avatar):

http://www.briangavindiamonds.com/diamonds/diamond-details/1.398-k-vs1-round-diamond-ags-104081043030

This one is pretty and a nice pendant size:
http://www.briangavindiamonds.com/diamonds/diamond-details/1.068-k-vs1-round-diamond-ags-104085572004

Good Old Gold also puts lots of performance metrics up so it's all there at a glance if you look there.


Alternatively, call Yekutiel at IDJ and let him work his magic. He's found fabulous stones for people and can do an idealscope as well.

It is so kind of you to make these recommendation! Thank you so much for taking the time! I

 

[bunnycat]

The poor HCA score should be an indication to stay away. I'd start by finding diamonds with a score under 2.0 and then filter from that based on your requirements for carat, color, and clarity.

You can't see leakage by looking at the video, so ask for an Ideascope image of the diamond instead and compare against this http://ideal-scope.com/reference-chart-ideal-scope-images/........... If you see a ring of white/gray under the table then you have some leakage.

Take a look at this table too for some guidance on what angles and percentages makes a super ideal cut!
https://www.pricescope.com/wiki/diamonds/diamond-grading-chart-round

This one is also an IGI graded stone. I don't know much about what reliability IGI may or may not have in relation to GIA graded stones if you are trying to compare color.

Are you looking for a stone below I? There may be better places for you to search if so.

Yes, I am. I bought a K not too long ago. its beautiful, and I don't mind the slight tint when looked at from the side. so I am open to lower colors. I have not seen a M in person though. I plan to have it set in 14 kt yellow gold bezel pendant. Hopefully the yellow tint is not that strong. what's a good place to search?

My suggestion is to look for something in the J/K range that has fluor. If you are looking to drop down to L/M, then Brian Gavin has a series cut specifically in the Cape colors. And in the J/K range I'd look in the Brian Gavin Blue line, which has fluor to help boost the face up color. No extra work or running number to be done, as they are all Ideal cut and all have light performance information added. You could also try Whiteflash, though they don't have specific series of stones like BG does so you'd have to weed through if you are looking for fluor, though they have their own specialty ideal cut as well. Sadly- I think inventory is low this close to V-day....

http://www.briangavindiamonds.com/diamonds/signature-diamonds/cape
http://www.whiteflash.com/

I don't know what size you are looking for, but here is a 1ct K at Whitflash:

http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-3738438.htm

and I considered this stone at BG and it was pretty, but we found one with fluor that was a little bigger and went with that (now in my avatar):

http://www.briangavindiamonds.com/diamonds/diamond-details/1.398-k-vs1-round-diamond-ags-104081043030

This one is pretty and a nice pendant size:
http://www.briangavindiamonds.com/diamonds/diamond-details/1.068-k-vs1-round-diamond-ags-104085572004

Good Old Gold also puts lots of performance metrics up so it's all there at a glance if you look there.


Alternatively, call Yekutiel at IDJ and let him work his magic. He's found fabulous stones for people and can do an idealscope as well.

It is so kind of you to make these recommendation! Thank you so much for taking the time! I

You are welcome! Since I just got through looking at k stones, the ideas are still fresh in the mind.

 

[ChristineRose]

IGI isn't necessarily horrible, but JA has literally hundreds of more or similar stones to look at, so there's no reason to get an IGI in this case.

 

[John P]

Just look at the appearance of the diamond under the table compared to the edge of the diamond, see how much darker it looks in the middle compared to the edge? There is a contrast in brightness in the head on view of edge of diamond compared to middle. This can signify a dulled diamond that appears lifeless in the middle due to leakage under the table (typical of steep deep diamonds)

I created this graphic to demonstrate gm89uk's comment. As predicted, this proportions set has some light-loss under the table. In softer lighting conditions, especially, it won't be as bright as diamonds returning more light to the viewer's eye.


The above uses a "perfect" ASET wireframe so it's not specific to an actual diamond. Consistency of faceting, indexing, 3D precision and other details all have an effect on an actual diamond's image. With that said, the above does demonstrate best-case light return vs. loss for those baseline proportions.

RE the OP's subject question: In the context of global cut-quality these proportions aren't a train-wreck. They are a candidate for AGS 2-3 light performance. The cut-quality in this example would not improve face-up color appearance, which might be desirable in lower colors depending on the buyer's goals. As a footnote, strong blue fluorescence could help in that regard, but there's no way to know without involving someone with the diamond in-hand. Fluor should be checked by an experienced gemologist, in any case.

Videos can vary and this isn't a reliable way to assess leakage, you need an idealscope/ASET for that, but it's some of the clues you can use.

The last sentence is 100% correct. Especially given so many different setups across the board. With that understood, a wide range of videos made by the same-seller in the same-setup is helpful because head-to-head comparisons are more plausible with standardization.

Hope it's interesting.

 

[mermi2015]

Hello. I know most people here swear by HCA scores but I think it has it's pitfalls and you should not select stones only because they have a HCA of less than 2. However, a high HCA score may definitely lead you to reject the diamond, which is not unreasonable. In this case, I find it strange, as a diamond manufacturer, as this diamond seems to have excellent cutting parameters, crown angle is a bit steep but table and total depth is great and there is no reason why this diamond shouldn't perform well.

The bigger issue I see is that this diamond has strong fluorescence. You are worrying about the HCA score whereas in all probability this diamond is going to be milky-looking and not have brilliant lustre/shine.

Thanks for your advice. According to the rep the fluorescence on this stone shouldn't be a problem. May even make the diamond look whiter. But you are right, that is something I should pay attention too.

 

[mermi2015]

IGI isn't necessarily horrible, but JA has literally hundreds of more or similar stones to look at, so there's no reason to get an IGI in this case.

I really hope igi antwerp lives up to its reputation. My order should arrive tomorrow. I end up buying the 1.06 ct K color. which is igi certified.

 

[mermi2015]

Just look at the appearance of the diamond under the table compared to the edge of the diamond, see how much darker it looks in the middle compared to the edge? There is a contrast in brightness in the head on view of edge of diamond compared to middle. This can signify a dulled diamond that appears lifeless in the middle due to leakage under the table (typical of steep deep diamonds)

I created this graphic to demonstrate gm89uk's comment. As predicted, this proportions set has some light-loss under the table. In softer lighting conditions, especially, it won't be as bright as diamonds returning more light to the viewer's eye.


The above uses a "perfect" ASET wireframe so it's not specific to an actual diamond. Consistency of faceting, indexing, 3D precision and other details all have an effect on an actual diamond's image. With that said, the above does demonstrate best-case light return vs. loss for those baseline proportions.

RE the OP's subject question: In the context of global cut-quality these proportions aren't a train-wreck. They are a candidate for AGS 2-3 light performance. The cut-quality in this example would not improve face-up color appearance, which might be desirable in lower colors depending on the buyer's goals. As a footnote, strong blue fluorescence could help in that regard, but there's no way to know without involving someone with the diamond in-hand. Fluor should be checked by an experienced gemologist, in any case.

Videos can vary and this isn't a reliable way to assess leakage, you need an idealscope/ASET for that, but it's some of the clues you can use.

The last sentence is 100% correct. Especially given so many different setups across the board. With that understood, a wide range of videos made by the same-seller in the same-setup is helpful because head-to-head comparisons are more plausible with standardization.

Hope it's interesting.

Thank you so much for your thorough explanation. It really helped me make up my mind. I've decided even the best-case scenario seems inadequate. Your comment on how the cut will not help hide the color made me think that the M color may be too much for me. Originally I was hoping with an excellent cut, the stone will at least look white face up. Thanks again!


I absolutely love this place. Everyone is super nice and willing to take time to help out newbies like me! I've learned so much. Thank you everyone!