Please confirm quality of this stone

[GFORCE100]

Hello all,

I'm pretty sure I know how good this diamond is but just want to confirm such with your opinions/knowledge if at all possible.

I have the diamond in front of me so I've seen it.

I'm interested in the beauty of the stone as perceived by others.

This diamond has 2 reports, one by GIA and one by AnchorCert and both specify the same F VVS1, no culet, thin to medium girlde, table size etc.

Report: GIA/AnchortCert (2 reports)
Shape: RB brilliant
Carat: 0.65ct
Color: F
Clarity: VVS1
Depth: 61.2/61.4% (depending on the report I look at)
Table: 55.0&
Crown %: 16.2
Pavilion %: 42.6
Girdle: Thin to Medium Faceted
Polish: Excellent
Symmetry: Excellent
Culet: None
Fluorescence: None
Measurements: 5.59-5.61x3.44mm or 5.59-5.62x3.43mm (depending on the report I look at)

Thanks for your time and effort.

 

[Regular Guy]

GForce,

Not an expert, and note that generally we are warned that % data is not as helpful as angle data when using the HCA as a tool for analyzing proportions for a diamond. But, based on using the % data, you have a sought after FIC, that has the chance of being quite lovely. Also, I think the low HCA score of .7 will help to minimize the chances your % data will be so inaccurate so as to be over 2 if done as an angle...best guess.

 

[Rhino]

Hi GForce,

Is this the same GForce I see floating around on the net?!?! Have we crossed paths before?

In any case the percentages of this stone suggest a 35.6-35.7 crown angle coupled with a 40.4 pavilion angle. This is very good... however there are still a number of variables missing if you''re really looking for the big picture. Now (finally) minor facets are playing a more vital role in the final cut grade of the diamond in both the new GIA and AGS systems. So ... if upper girdles are cut in such a way, this will disqualify the stone from receiving ideal grade and also impact the brightness. Same can be said for lower girdles and to a lesser extent stars. So if one is to truly determine if the stone meets the new ideal criteria a basic Sarin will not do the job anymore.

The main angles suggest a current AGS ideal grade but that is with 80% lower girdles and 50% stars.

Here are a few examples of what you *may* have. The only alterations I''m making in this model are with the lower girdles. Usually when discussing lower girdles I generally refer to lower girdle length but in this case, since I''m using DiamCalc to make the models I''m using lower girdle depth (instaed of length). The stars are set at 55% and upper girdles at 42.8 degrees (for contrast).

As you can see, the proportions you list (without minor facet information or variances) can yield quite a few different results and obviously very different looking diamonds.

If you take note the pavilion mains are starting to get dark which indicates this is right on the threshold of GIA grade 1 and may or may not get ideal grade, may fall either way. The next graphic in my next post demonstrates what happens if we just bump the pavilion angles to 40.5.

 

[Rhino]

Note how the pav mains maintain even brightness by bumping the angles slightly. I cover the observance of this feature in our tutorial on the GIA Cut system and some of the observations I note. This would *definitely* make a Grade1 as the mains are lit up properly. If the minors are cut right it should be a fine stone but without that info it''s a little more tough to give a professional opinion. If you can get a model of the stone that would really help.

 

[GFORCE100]

Date: 7/1/2005 10:52:08 AM
Author: Rhino
Hi GForce,

Is this the same GForce I see floating around on the net?!?! Have we crossed paths before?

In any case the percentages of this stone suggest a 35.6-35.7 crown angle coupled with a 40.4 pavilion angle. This is very good... however there are still a number of variables missing if you're really looking for the big picture. Now (finally) minor facets are playing a more vital role in the final cut grade of the diamond in both the new GIA and AGS systems. So ... if upper girdles are cut in such a way, this will disqualify the stone from receiving ideal grade and also impact the brightness. Same can be said for lower girdles and to a lesser extent stars. So if one is to truly determine if the stone meets the new ideal criteria a basic Sarin will not do the job anymore.

The main angles suggest a current AGS ideal grade but that is with 80% lower girdles and 50% stars.

Here are a few examples of what you *may* have. The only alterations I'm making in this model are with the lower girdles. Usually when discussing lower girdles I generally refer to lower girdle length but in this case, since I'm using DiamCalc to make the models I'm using lower girdle depth (instaed of length). The stars are set at 55% and upper girdles at 42.8 degrees (for contrast).

As you can see, the proportions you list (without minor facet information or variances) can yield quite a few different results and obviously very different looking diamonds.

If you take note the pavilion mains are starting to get dark which indicates this is right on the threshold of GIA grade 1 and may or may not get ideal grade, may fall either way. The next graphic in my next post demonstrates what happens if we just bump the pavilion angles to 40.5.

Hello all and hello again Rhino, yes it's me and I've come across such stone which is seeming to me as a somewhat nice diamond hence the thread.

The percentage values are all off the 2nd report (AnchorCert) so I assume therefore that they must be pretty close to the actual truth. As for other measurements GIA states the diamond depth as 61.4% and AnchorCert as 61.2% but both agree on the table size which is 55%, symmetry, polish, color, fluorescence, and actual size.

I can see the arrows when looking through the top of the diamond even without any magnification and they do look very symmetrical all over.

What puzzles me is that this diamond was sold as "Ideal cut" but wasn't sold as "Hearts & Arrows". Despite this however AnchortCert states this is a H&A's diamond when they were grading it. Add to this the fact I can see the arrows makes me believe that due to less demand some ideal cuts won't get marketed as H&A's correct?

The arrows themselves look like the 82% image you've posted, they're between medium and thin.

I know the girdle thickness percentages should these help any?

 

[GFORCE100]

Date: 7/1/2005 7:14:20 AM
Author: Regular Guy
GForce,

Not an expert, and note that generally we are warned that % data is not as helpful as angle data when using the HCA as a tool for analyzing proportions for a diamond. But, based on using the % data, you have a sought after FIC, that has the chance of being quite lovely. Also, I think the low HCA score of .7 will help to minimize the chances your % data will be so inaccurate so as to be over 2 if done as an angle...best guess.

Yes 0.7 on the HCA suggests it''s an excellent looking diamond, with EX, EX, EX, and VG.

I guess the more opinions brought forward the more I''ll be able to ascertain it''s actual cut quality so thanks,

 

[GFORCE100]

Girdle thickness as indicated on the report is 0.89-1.61%

 

[GFORCE100]

Nothing more to add anyone?