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Why is this diamond so ugly

D

DiamondsAndDior

Rough_Rock
Joined
Feb 12, 2019
Messages
62
I came across this while searching for diamonds with “ideal” proportions. It has a 57 table, 60.5 depth, 34.5 crown and 40.8 pavilion. However, it looks really ugly in the video. The arrows are really thick and dark and they look like blobs of black. Is there something about the proportions that make it look this way, or is it just bad photo/video quality?

https://www.jamesallen.com/mobile/l...-i-color-si2-clarity-excellent-cut-sku-620304

C2FBC57C-30BF-4AB0-B19F-2CF309E6FBF4.jpeg B5180893-F6E3-451F-8CB7-7044BD82F5F6.jpeg
 
Not an expert on this stuff, but my guesses are:
1. Not quite deep enough given how large (relatively) the table is
2. Something about the inclusions is making everything look dark and bad
3. Something about GIA rounding making the proportions seem ok even though there are some weird numbers hiding in there.
 
Bad videophotography.
The camera is too close and the diamond is reflecting the black body of the camera. This explains blobs of black around the arrowheads and around the table reflection in the middle.
The dull lighting makes it look even worse.
Notice the GIA report is from mid 2015. The video was probably taken back then when JA's photography settings were a bit less consistent.

LGF 70% explains thick arrows.

It is not a good way to present a $90k stone.
 
flyingpig said:
Bad videophotography.
The camera is too close and the diamond is reflecting the black body of the camera. This explains blobs of black around the arrowheads and around the table reflection in the middle.
The dull lighting makes it look even worse.
Notice the GIA report is from mid 2015. The video was probably taken back then when JA's photography settings were a bit less consistent.

LGF 70% explains thick arrows.

It is not a good way to present a $90k stone.
Click to expand...
With better video/lighting would it look like a top stone, or just "ok"? It's so interesting that it looks SO BAD, but the numbers look fine. That's why I figured it was a rounding issue with GIA, meaning the averages were hiding some weird values.
 
lovedogs said:
With better video/lighting would it look like a top stone, or just "ok"? It's so interesting that it looks SO BAD, but the numbers look fine. That's why I figured it was a rounding issue with GIA, meaning the averages were hiding some weird values.
Click to expand...
I think it is potentially a top GIA ex. I do not see any obvious leakage under the table or severe girdle treatment. 70% LGF is interesting.

In order to get such obstruction issue, you need a shallow crown or a shallow pavilion. I just do not see it possible with 58/34.5/40.8 even considering GIA rounding and angle deviations.

It may or may not be a good stone. But the camera is definitely too close for sure.
 
It’s the 70% lgf
 
It is the 70% lgf% does not work well with that combo plus the inclusions are making it cloudy
Overall as stated above, train wreck.
 
Karl_K said:
It is the 70% lgf% does not work well with that combo plus the inclusions are making it cloudy
Overall as stated above, train wreck.
Click to expand...
makes sense. I was thinking that the 70% LGF was due to the depth, but I think I was incorrect, and maybe it's DUE to the 70% LGF that it looks weirdly shallow.
 
How would one know what percent LGF should be? I’m still learning didn’t realize that number really mattered.
 
lovedogs said:
makes sense. I was thinking that the 70% LGF was due to the depth, but I think I was incorrect, and maybe it's DUE to the 70% LGF that it looks weirdly shallow.
Click to expand...

The mains are the shallowest facets on the pavilion - shorter halves are steeper than longer halves (more angular differential between table plane and lower halves). WF has a good summary -
https://www.whiteflash.com/about-diamonds/diamond-education/facets-the-lower-halves.htm

In this case the mains are obstructing and the halves are not; if LGF had been longer, well, maybe they'd be obstructing as well. Clarity issues + less-than-stellar optical symmetry + camera too close == hot mess... I'd bet if they moved the camera out a few mm it'd look a whole lot better.
 
Thanks all, this is really interesting.

To clarify, I’m NOT looking to buy this stone. I just came across it in my search when I put in my parameters. It was so ugly that it caught my eye and I was just curious to understand why :)
 
Not speaking on this diamond specifically, but in general consider the following:

For reference (all graphics courtesy of John Pollard) here are how the percentages of LGF can change the look of the diamond. This chart does not include 70% LGF but you can see the changes each 5%.

Lower Girdle 75-85.jpg

Take into account that all LGFs are rounded to the nearest 5% and you can see how even this number doesn't tell the whole story - these would all be listed as 80% LGF


Lgf - All called 80.jpg

This means a diamond with a 70% LGF could, in fact, be at 68%.

All of the proportions in the cut do matter. The Table, Depth, CA and PA are good parameters to begin with - further examination of the particulars (and light performance images) will certainly reveal even more about a diamond's performance.
 
Are there optimal LGFs for certain proportions? For example, it is generally recommended to pair a lower crown with a higher pavilion and vice versa. It there a similar type of general recommendation for LGFs?
 
Diamond_Hawk said:
Not speaking on this diamond specifically, but in general consider the following:

For reference (all graphics courtesy of John Pollard) here are how the percentages of LGF can change the look of the diamond. This chart does not include 70% LGF but you can see the changes each 5%.

Lower Girdle 75-85.jpg

Take into account that all LGFs are rounded to the nearest 5% and you can see how even this number doesn't tell the whole story - these would all be listed as 80% LGF


Lgf - All called 80.jpg

This means a diamond with a 70% LGF could, in fact, be at 68%.

All of the proportions in the cut do matter. The Table, Depth, CA and PA are good parameters to begin with - further examination of the particulars (and light performance images) will certainly reveal even more about a diamond's performance.
Click to expand...
I'm sure this has been covered before... but why do GIA round to such an extent?

It seems madness!

Surely it would be easier to add all of them together and then divide by the number of them, in order to get an average?

Or are GIA being 'soft' so the industry don't hate them? lol
 
OoohShiny said:
I'm sure this has been covered before... but why do GIA round to such an extent?

It seems madness!

Surely it would be easier to add all of them together and then divide by the number of them, in order to get an average?

Or are GIA being 'soft' so the industry don't hate them? lol
Click to expand...

Business decisions are made for all kinds of reasons. My hope is that educated consumers will be able to sort through it all and live quietly (or loudly) with the fact that their bling is the best bling on the block .
 
DiamondsAndDior said:
Are there optimal LGFs for certain proportions? For example, it is generally recommended to pair a lower crown with a higher pavilion and vice versa. It there a similar type of general recommendation for LGFs?
Click to expand...

 
GIA EX/EX/EX :eek2:
 
CareBear said:
GIA EX/EX/EX :eek2:
Click to expand...
Exactly!
Forget about the steep/deeps. If you ever wanted a poster child for how overly wide the Triple Ex grade is and how you need much more info than is contained on a GIA report is needed to confirm cut quality, this one is right up there!
It demonstrates how important the so called "minor facets" are in terms of impact on light performance. Long stars and short lowers, and how GIA rounding of these measurements hampers your ability to predict actual cut quality.
 
I use the Pricescope search function to look for stones and one of the filters I apply is HCA=Excellent, and this stone falls into that category. PS has helped me learn that the way GIA rounding is done can be so deceiving!
 
The main issue is the camera is too close or the macro lens is too large because it is a bigger than usual stone.
Capture.JPG Those of you who like the new versions of old cuts would love this stone.
 
DiamondsAndDior said:
I use the Pricescope search function to look for stones and one of the filters I apply is HCA=Excellent, and this stone falls into that category. PS has helped me learn that the way GIA rounding is done can be so deceiving!
Click to expand...
Nothing deceiving in this case by GIA.
It is the photo setup
 
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