why is this diamond not ACA?

[ezwinner701]

http://www.whiteflash.com/round_ideal_cut/Round-Ideal-Cut-cut-diamond-70092.htm#

is it because it is GIA graded and not AGS? the HCA shows a 1.1 TIC.

 

[diamondseeker2006]

I think the girdle being slightly thick to thick would probably rule it out from being AGS0. The thick girdle accounts for some of the weight, so it does not have the 8.2mm diameter that a 2 carat stone optimally would have. I am guessing that is what puts in in the GIA vg category as well. But it looks like a pretty diamond!

(Oh, and I think the HCA is assuming a girdle that is not thick, so the HCA might not be accurate for this particular stone. However, you do have the idealscope and a photo, so I wouldn't worry about the HCA score anyway.)

 

[dfm00]

I would think the thick (and maybe even slightly thick) girdle precluded it from meeting ACA (and AGS000/GIA EX?) standards. So WF decided to send it to GIA since it had no chance to be ACA. I don''t think any of this means the stone can''t be a great performer, though it will hide some weight in the girdle and be a bit small in diameter for a 2c.

Dave

 

[tanalasta]

Two other reasons I can think of.

The Sarin shows that the crown angles are not as tightly cut as they could - 34.0 to 34.6 with the average of 34.3 degrees. 34.0 may be considered slightly shallow by some. The GIA report rounds to 34.5 and Pav. 40.8 which some would consider ''perfect''.

ACA stones show H&A - I suspect perhaps this stone did not ''quite'' make the H&A criteria.

You can always ask Whiteflash why this stone did not meet the cut.

As the stone ''just'' made the 2.00 Ct mark (cutter would be pleased ... 2.00 = profit > 1.99) ... one wonders if there was some compromises made there to retain carat weight.

The clouds and the surface graining mentioned in the GIA report may have a negative effect on the stone''s overall ''cut grade'' - who knows? One of the experts may have a comment. Still, a VS2 should be relatively eye-clean and the inclusions have a minimal (if any) effect. I haven''t had a look at the 40x magnification photo.

ASET and IS appear ''perfect'' so there is every chance this stone - if you can afford it - is a good buy.

 

[hoorray]

Often the answer to this question is "because of the hearts". ACA has a very exacting H&A definition that they require, and sometimes, if the hearts are not perfect, it won''t make the grade. It doesn''t mean it won''t be a top preforming stone tho. Ask WF.

 

[JohnQuixote]

Hi all.

''Expert Selection'' diamonds represent value for the money. This is a beautiful EX EX brilliant with wonderful performance but every last detail must conform to Brian Gavin''s standards if it were to be ACA. DiamondSeeker & dfm were on the money in this case; it''s the girdle thickness and resultant spread for weight. That''s why Brian sent it to GIA for grading.

Some of these details are more visible than others. As lop mentioned, you may come across ES rounds which seem to have everything in place. If not ACA it may simply be because our own requirements for pavilion (hearts) patterning or it could even that polish or symmetry would have received a grade less than Ideal.

 

[JohnQuixote]

Date: 1/21/2007 8:50:47 AM
Author: tanalasta

As the stone 'just' made the 2.00 Ct mark (cutter would be pleased ... 2.00 = profit > 1.99) ... one wonders if there was some compromises made there to retain carat weight.

Absolutely. The rough was shaped so that the girdle had to remain 'thick' in places in order to recover 2.0 carats. Still great proportions though. It was a small compromise, but sharp analysts will take note.

The clouds and the surface graining mentioned in the GIA report may have a negative effect on the stone's overall 'cut grade' - who knows? One of the experts may have a comment. Still, a VS2 should be relatively eye-clean and the inclusions have a minimal (if any) effect. I haven't had a look at the 40x magnification photo.

ASET and IS appear 'perfect' so there is every chance this stone - if you can afford it - is a good buy.

No worries on the clouds or graining. Many times a diamond grading report will list surface graining, pinpoints, additional clouds, etc. as 'not shown.' The diamond's report is just noting that these things exist for sake of thoroughness. 'Not shown' means they are non-issues (an exception is an SI2 diamond where clouds set the grade).

Surface Graining is diamond structural irregularity. You can see it with a microscope. The diamond graining may resemble faint facet junction lines, or cause a grooved or wavy surface. They look like polishing lines, but they often cross facet junctions where polishing lines don't. It is a natural characteristic of the diamond crystal, and not a reflection of the diamond's cut quality. Additional Clouds are mentioned, since they were taken into consideration for the diamond's total clarity grade. Not drawing them is standard procedure and nothing to worry about.

Good discussion.

 

[strmrdr]

I think it met a cold hearted chick and got a broken heart.

No light to play with and no hand to cuddle another heart just broke away.

She ran off with the 5ct champaign.

No light to play with and no hand to cuddle another heart just broke away.

Then stuffed back in the cold dark vault.

No light to play with and no hand to cuddle another heart just broke away.

Then along came Brian and said hey your not good enough to wear an ACA.

No light to play with and no hand to cuddle another heart just broke away.

Then it got stuffed back in the cold dark vault.

No light to play with and no hand to cuddle another heart just broke away.

 

[Maisie]

Oh no! Thats sad.

It can come and live with me!!