HCA not giving expected results with AGS0--am I doing it wrong?

[Picabia]

I found a diamond with both GIA and, at the bottom of the IGA cert, AGS#s. It scored a "0" on cut, so I assumed it would fall into that little box on the HCA. But it didn''t. Did I do something incorrectly? Here are the stats from AGS:

AGS Round Weight .920 ct total grade: 0
Diameter 6.21mm (6.20-6.23)
Depth: 3.89mm 62.6%
Table 3.48mm 56%
Crown 34.6 (34.4-35.1) 15.4%
Pavilion 41.2 (40.9-41.5) 43.7%
Culet: .4% pointed
Girdle 2.1%

 

[stone-cold11]

What is the date of the AGS report? A very old report will use proportion cut grade, a gold/diamond quality report will use proportion cut grade, different criteria for achieving AGS0. A diamond quality document report will use performance based cut grade, these use simulation on the actual proportion of the stone to determine the performance, so an AGS0 grade can be issue to stone outside of AGS proportions if the proportions work well with other minor facets and symmetry.

 

[Allison D.]

If those measurement you listed are correct, the HCA is dinging the stone based on the pavilion angle/crown angle combo.

 

[Picabia]

The AGS report doesn''t seem to be dated. It''s just a small cut-out attached to an IGA report. But the numbers are the same on both and the GIA is from December 09. Is this strange? I would post the cert, but I''m not familiar with the copyright law.

 

[Lorelei]

Date: 5/5/2010 9:03:36 AM
Author:Picabia
I found a diamond with both GIA and, at the bottom of the IGA cert, AGS#s. It scored a '0' on cut, so I assumed it would fall into that little box on the HCA. But it didn't. Did I do something incorrectly? Here are the stats from AGS:

AGS Round Weight .920 ct total grade: 0
Diameter 6.21mm (6.20-6.23)
Depth: 3.89mm 62.6%
Table 3.48mm 56%
Crown 34.6 (34.4-35.1) 15.4%
Pavilion 41.2 (40.9-41.5) 43.7%
Culet: .4% pointed
Girdle 2.1%

Hi Picabia

This happens sometimes and it probably isn't anything to do with the date, could be the crown and pavilion angles are nudging it out of the box, a steeper pavilion in particular won't always fare so well on the HCA, do you have any images of the diamond?

ETA - ditto my esteemed friend Allison!

 

[Lorelei]

Date: 5/5/2010 9:16:34 AM
Author: Picabia
The AGS report doesn''t seem to be dated. It''s just a small cut-out attached to an IGA report. But the numbers are the same on both and the GIA is from December 09. Is this strange? I would post the cert, but I''m not familiar with the copyright law.

You can find sometimes that a stone has 2 reports, this happens occasionally, you are fine to post the reports if you wish.

 

[Picabia]

Thanks everyone. I don''t have any pics of the stone, but I was sticking to only diamonds that score below a 2 on the scale to look at in person. Should I include this as a possibility? The only thing I don''t like is how narrow it is (the other stone I''m looking at, which did score below 2, has more spread, and I have size anxiety...).

 

[stone-cold11]

No, that is not AGS issued cut grade, just a sarin scan output, maybe into an AGS cut grading software, depends on how updated the software is, the cut grade maybe based on the old proportion based grading or the new performance based grading system.

 

[Lorelei]

Date: 5/5/2010 9:24:41 AM
Author: Picabia
Thanks everyone. I don't have any pics of the stone, but I was sticking to only diamonds that score below a 2 on the scale to look at in person. Should I include this as a possibility? The only thing I don't like is how narrow it is (the other stone I'm looking at, which did score below 2, has more spread, and I have size anxiety...).

Ok that looks like a Sarin scan for the other numbers, not actually a grading report from AGS, as GIA round the numbers more detailed measurements can be useful to have. This diamond is a bit deep at 62.6% for that type of diamond, although the spread is ok there are lots of well cut stones out there, if you have time see what else is available.

 

[Picabia]

Ok, so (correct me if I'm wrong), that Sarin scan basically just lets them know how precise the cut measurements are, but this has no bearing on the "0" grade it was giving and this is not an ideally cut stone, correct?

Thanks so much everyone. There is a lot more to know than I was expecting (er, hoping?) in order to find a really great stone. You guys make it much easier.

 

[Lorelei]

Date: 5/5/2010 9:37:42 AM
Author: Picabia
Ok, so (correct me if I'm wrong), that Sarin scan basically just lets them know how precise the cut measurements are, but this has no bearing on the '0' grade it was giving and this is not an ideally cut stone, correct?

A Sarin scan is a machine that measures the proportions of the stone but it isn't the same thing as AGS's grading which can give the AGS0 cut grade to diamonds which meet their standards. Some vendors have Sarin scanners available and can run their stones through to get more info. The accuracy can vary according to the calibration of the machine and other factors, a small piece of dust can affect the readings.

The diamond in question appears to be a well cut stone but its not the cream of the crop such as the branded h&a diamonds we often see here, it depends on what you are looking for, sometimes a Mercedes can be a good choice compared to a Ferrari!

Only AGS can say if this diamond would meet their criteria to get the AGS0 cut grade, it might not and there is no way we can know how AGS would grade it.

Read more on AGS grading here, www.agslabs.com and use the consumer section.

 

[Picabia]

Thanks Lorelei! More reading for me...

 

[Lorelei]

Date: 5/5/2010 9:44:33 AM
Author: Picabia
Thanks Lorelei! More reading for me...

You are welcome!

 

[Laila619]

It''s not a ''bad'' stone, but it will probably show some slight leakage due to the pavilion angle with that crown. When I was shopping, I found the best diamonds generally had pavilion angles in the 40.7-40.8 range.

 

[Dreamer_D]

I think I would consider this diamond if the price was reallyt good, since that could offset any potential slight decriments in appearance, but if the price is in line with others you are considering, there are lots of diamonds out there to choose from so I would just stick with the stricter criteria.