How can this stone score AGS Ideal for light performance

[flyingpig]

I just have not seen so much green and dark green in a AGS 000 stone

 

[Texas Leaguer]

Must have just barely squeaked by the ray tracing. I would imagine that it had some deductions.

 

[Andelain]

Who has that one? I'm curious how old it is.

 

[kenny]

Excellent example of why a few posters here should stop saying, "Oh if it's AGS 0 you don't need any other cut tools."

I wouldn't buy a white diamond that does not do well by ALL cut tools.

 

[gr8leo87]

Excellent example of why a few posters here should stop saying, "Oh if it's AGS 0 you don't need any other cut tools."

I wouldn't buy a white diamond that does not do well by ALL cut tools.

Very well said.

While AGS0 is good this is a perfect example of why AGS 0 is not holy grail of diamond cuts.

This trend would be consistent in stones with PA deeper than 41°. These stones will not score well on HCA and they would still be AGS0s.

 

[gr8leo87]

Also it would be interesting to see diamonds making AGS0 and not making GIA Ex for cut. that is stone with PAs shallower than 40.6 averaged.

 

[flyingpig]

http://www.jamesallen.com/loose-diamonds/round-cut/0.90-carat-j-color-vs1-clarity-ideal-cut-sku-722705

http://www.jamesallen.com/loose-diamonds/round-cut/0.90-carat-j-color-vs1-clarity-ideal-cut-sku-318989


For me, it is no brainer. Stone #1, given the fact that it is actually cheaper..

Neither was my pick. I thought it would be interesting to share

 

[Andelain]

.
For me, it is no brainer. Stone #1, given the fact that it is actually cheaper..

Neither was my pick. I thought I would be interesting to share

It is for me, too. In fact, if stone #1 was a higher color I'd be making up an excuse to buy it.

 

[sharonyanddave]

I just have not seen so much green and dark green in a AGS 000 stone

Bad scan helped the stone, rare but it happens.

 

[gr8leo87]

I just have not seen so much green and dark green in a AGS 000 stone

Bad scan helped the stone, rare but it happens.

That's a dangerous presumption and reflects badly on AGS. I would guess they'd run a scan at least twice on a stone just to be sure and probably use the best machine out there, may be a secret proprietary version of top of the line Helium.

 

[diamondseeker2006]

Totally agree with Kenny that AGS 000 shouldn't ever be bought blindly, especially with crazy measurements like that! What were they thinking?!

 

[yssie]

I just have not seen so much green and dark green in a AGS 000 stone

Uncommon, but certainly not unheard-of, as others have commented on already

Bad scan helped the stone, rare but it happens.

That's a dangerous presumption and reflects badly on AGS. I would guess they'd run a scan at least twice on a stone just to be sure and probably use the best machine out there, may be a secret proprietary version of top of the line Helium.
Why? It's a sub-1ct J VS1 - not a particularly valuable stone, no special provenance that would merit further investigation...
Routine AGS grading is done w/ Sarin, the AGS research lab uses Helium for internal affairs I believe.

 

[flyingpig]

I just have not seen so much green and dark green in a AGS 000 stone

Uncommon, but certainly not unheard-of, as others have commented on already

Bad scan helped the stone, rare but it happens.

That's a dangerous presumption and reflects badly on AGS. I would guess they'd run a scan at least twice on a stone just to be sure and probably use the best machine out there, may be a secret proprietary version of top of the line Helium.
Why? It's a sub-1ct J VS1 - not a particularly valuable stone, no special provenance that would merit further investigation...
Routine AGS grading is done w/ Sarin, the AGS research lab uses Helium for internal affairs I believe.

out of curiosity. What combination of 4c makes a stone particularly valuable??

 

[gr8leo87]

I just have not seen so much green and dark green in a AGS 000 stone

Uncommon, but certainly not unheard-of, as others have commented on already

Bad scan helped the stone, rare but it happens.

That's a dangerous presumption and reflects badly on AGS. I would guess they'd run a scan at least twice on a stone just to be sure and probably use the best machine out there, may be a secret proprietary version of top of the line Helium.
Why? It's a sub-1ct J VS1 - not a particularly valuable stone, no special provenance that would merit further investigation...
Routine AGS grading is done w/ Sarin, the AGS research lab uses Helium for internal affairs I believe.

Simply because they would want to be accurate. It takes less than minute for a scan. 2 scans are better than one.

And it may not be a bad scan after all.

 

[yssie]

I just have not seen so much green and dark green in a AGS 000 stone

Uncommon, but certainly not unheard-of, as others have commented on already

Bad scan helped the stone, rare but it happens.

That's a dangerous presumption and reflects badly on AGS. I would guess they'd run a scan at least twice on a stone just to be sure and probably use the best machine out there, may be a secret proprietary version of top of the line Helium.
Why? It's a sub-1ct J VS1 - not a particularly valuable stone, no special provenance that would merit further investigation...
Routine AGS grading is done w/ Sarin, the AGS research lab uses Helium for internal affairs I believe.

out of curiosity. What combination of 4c makes a stone particularly valuable??

No idea what the bar for "valuable" is but I'm confident it's larger and higher-colour than the stone in question

 

[yssie]

And it may not be a bad scan after all.

Agreed - in fact, not at all sure what makes the poster of this assertion so certain that this is the case.

 

[sharonyanddave]

And it may not be a bad scan after all.

Agreed - in fact, not at all sure what makes the poster of this assertion so certain that this is the case.

I can be 100% certain the arrows should not be red.
Whether its a poor scan or some other artefact I can't be certain however the image and its flaws are predictive of the datasets that were used to set the performance grade.

 

[yssie]

And it may not be a bad scan after all.

Agreed - in fact, not at all sure what makes the poster of this assertion so certain that this is the case.

I can be 100% certain the arrows should not be red.

Why not? This is exactly what we would expect w/ stones w/ steeper pavilions.
Steeper pavilion = steeper mains = mains returning light incident on the stone from 45-75deg from the girdle plane (red in ASET) rather than reflecting blue (75-90deg)
https://www.americangemsociety.org/uploads/154731296495014.pdf

 

[Serg]

And it may not be a bad scan after all.

Agreed - in fact, not at all sure what makes the poster of this assertion so certain that this is the case.

I can be 100% certain the arrows should not be red.

Why not? This is exactly what we would expect w/ stones w/ steeper pavilions.
Steeper pavilion = steeper mains = mains returning light incident on the stone from 45-75deg from the girdle plane (red in ASET) rather than reflecting blue (75-90deg)
https://www.americangemsociety.org/uploads/154731296495014.pdf

 

[sharonyanddave]

And it may not be a bad scan after all.

Agreed - in fact, not at all sure what makes the poster of this assertion so certain that this is the case.

I can be 100% certain the arrows should not be red.

Why not? This is exactly what we would expect w/ stones w/ steeper pavilions.
Steeper pavilion = steeper mains = mains returning light incident on the stone from 45-75deg from the girdle plane (red in ASET) rather than reflecting blue (75-90deg)
https://www.americangemsociety.org/uploads/154731296495014.pdf

AGSL uses ASET33.5 Blue Maps for images on their reports (2/3 ASET30 and 1/3 ASET40) as this is supposed to represent close to what datasets they are using for their LP grading.

This is the 'generated map' using lighting for ASET 33.5 for those proportions on that grading report as close as I can make it and assuming perfect symmetry which we know this diamond is not.

Depending upon the assymetry, rounding, and the scan error this stone is right on the border of AGSL 0 and AGSL (2, 3 and 4).
You would need to increase the crown angle to 36.2 and above to get all red arrows.

 

[yssie]

And it may not be a bad scan after all.

Agreed - in fact, not at all sure what makes the poster of this assertion so certain that this is the case.

I can be 100% certain the arrows should not be red.

Why not? This is exactly what we would expect w/ stones w/ steeper pavilions.
Steeper pavilion = steeper mains = mains returning light incident on the stone from 45-75deg from the girdle plane (red in ASET) rather than reflecting blue (75-90deg)
https://www.americangemsociety.org/uploads/154731296495014.pdf

AGSL uses ASET33.5 Blue Maps for images on their reports (2/3 ASET30 and 1/3 ASET40) as this is supposed to represent close to what datasets they are using for their LP grading.

This is the 'generated map' using lighting for ASET 33.5 for those proportions on that grading report as close as I can make it and assuming perfect symmetry which we know this diamond is not.

Depending upon the assymetry, rounding, and the scan error this stone is right on the border of AGSL 0 and AGSL (2, 3 and 4).
You would need to increase the crown angle to 36.2 and above to get all red arrows.

Thank you!
I have learnt something today!

 

[flyingpig]

Great information indeed. Thank you