Why is this diamond so ugly

[DiamondsAndDior]

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

 

[lovedogs]

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.

 

[flyingpig]

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.

 

[lovedogs]

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.

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.

 

[flyingpig]

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.

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.

 

[whitewave]

It’s the 70% lgf

 

[whitewave]

https://www.pricescope.com/community/threads/sorry-stupid-question-what-is-lgf.61176/

 

[OcnGypZ]

The plot is a train wreck and the stone is priced accordingly.

 

[Karl_K]

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.

 

[lovedogs]

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.

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.

 

[Pimberly]

How would one know what percent LGF should be? I’m still learning didn’t realize that number really mattered.

 

[yssie]

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.

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.

 

[Dancing Fire]

b/c 90K will not buy you a nice 5.75ct stone. Here ya go...

https://www.briangavindiamonds.com/diamonds/diamond-details/5.392-h-vs1-round-diamond-bfg-785919

 

[DiamondsAndDior]

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

 

[Diamond_Hawk]

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%.



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




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.

 

[DiamondsAndDior]

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?

 

[OoohShiny]

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%.



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




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.

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

 

[Diamond_Hawk]

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

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 .

 

[gm89uk]

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?

 

[CareBear]

GIA EX/EX/EX

 

[Texas Leaguer]

GIA EX/EX/EX

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.

 

[DiamondsAndDior]

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!

 

[Garry H (Cut Nut)]

The main issue is the camera is too close or the macro lens is too large because it is a bigger than usual stone.
Those of you who like the new versions of old cuts would love this stone.

 

[Garry H (Cut Nut)]

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!

Nothing deceiving in this case by GIA.
It is the photo setup