Cut Confusion

[kingfish]

Hi,

I would like to know how I can use the Holloway Cut Adviser to assess the cut of a GIA certified diamond. Unless I am missing something, the GIA cut score of excellent means little since it isn''t based on the crown or pavilion angles. Just having good depth and table percentages seems to be part of the picture.

My question: How can I assess the worth of a GIA certified stone which I am looking at purchasing from an online vender? Should I just stick with AGS Certified stones, which I can use the Halloway Cut Adviser with?

 

[honey22]

I believe that not all GIA certs show these numbers. Can you go to the GIA website, enter the stone;s weight and the cert # it might bring up the numbers you need.

Many of the GIA certs do have this info on it, and you can use these numbers in the HCA.

If you want to buy an diamond the ''easy way'' you can always look for an AGS Ideal cut stone (also referred to as AGS 000) which has scored a 0 for light performance (the best grade is 0). This will guarantee you a great performing stone. Note that it won''t guarantee you a true H&A stone (you need to get H&A images for this). Another note, AGS only has Ideal grades for their rounds and princess stones, not the other fancy shapes.

 

[Lorelei]

Date: 8/27/2008 4:55:21 AM
Author:kingfish
Hi,

I would like to know how I can use the Holloway Cut Adviser to assess the cut of a GIA certified diamond. Unless I am missing something, the GIA cut score of excellent means little since it isn''t based on the crown or pavilion angles. Just having good depth and table percentages seems to be part of the picture.

My question: How can I assess the worth of a GIA certified stone which I am looking at purchasing from an online vender? Should I just stick with AGS Certified stones, which I can use the Halloway Cut Adviser with?

Look at the date on the report, it could be pre cut grade, GIA have only been grading for cut and providing C &P angles since early 2006, so if this report is from before that time, it won''t have that info. What you could do is to ask the vendor to run a Sarin report on this diamond, this would give detailed measurements of this stone.

 

[John P]

Presuming that you're talking about round brilliants, GIA reports after 2006 will have c/p angles and a cut grade. They don't issue cut grades for fancy shapes (and of course the HCA is intended for RBs only)

Honey was referring to GIA's report check service: http://www.gia.edu/reportcheck/

If you have the grading report # and carat weight you can retrieve some data on diamonds dating back to 2001. Those after 2004 usually have c/p angles listed.

 

[brightstone]

I just bought a stone with that exact same situation (GIA 2005 certified excellent cut, but lacking info on crown and pavillion). I requested a Sarin report from James Allen, it took a day or two, but that solved the problem! Can you request one for yours?

 

[kingfish]

Guys, can you confirm that I have this right. In order for me to obtain the pavilion and crown angles I either need:

1) An AGS Certified stone;
2) A GIA certified stone, certified in or after 2006; or
3) A pre 2006 GIA certified stone where the vendor supplies a sarin report?

Am I understanding this correctly?

 

[John P]

2) A GIA certified stone, certified in or after 2006; or

If it was graded in or after 2004 the data may be accessible at GIA Report Check (linked above) even if it's not on the report.

3) A pre 2006 GIA certified stone where the vendor supplies a sarin report?

If the seller has a scanner he/she can supply a scan for any loose diamond.

 

[Garry H (Cut Nut)]

Date: 8/27/2008 6:52:19 PM
Author: John Pollard

2) A GIA certified stone, certified in or after 2006; or

If it was graded in or after 2004 the data may be accessible at GIA Report Check (linked above) even if it''s not on the report.

3) A pre 2006 GIA certified stone where the vendor supplies a sarin report?

If the seller has a scanner he/she can supply a scan for any loose diamond.

If the seller can give you an ideal-scope or aSEt image then it''s paper scissors rock

 

[HariSeldon]

Date: 8/27/2008 7:24:54 PM
Author: Garry H (Cut Nut)

Date: 8/27/2008 6:52:19 PM

Author: John Pollard

2) A GIA certified stone, certified in or after 2006; or

If it was graded in or after 2004 the data may be accessible at GIA Report Check (linked above) even if it''s not on the report.

3) A pre 2006 GIA certified stone where the vendor supplies a sarin report?

If the seller has a scanner he/she can supply a scan for any loose diamond.

If the seller can give you an ideal-scope or aSEt image then it''s paper scissors rock

side note: i never could get my head wrapped around why paper beats rock... i mean come on paper << rock...

 

[John P]

I agree. Buy the rock, not the paper.

 

[HariSeldon]

Date: 8/27/2008 7:51:55 PM
Author: John Pollard
I agree. Buy the rock, not the paper.

i see what you did there

lol

 

[Garry H (Cut Nut)]

Date: 8/27/2008 7:51:55 PM
Author: John Pollard
I agree. Buy the rock, not the paper.

I go for scissors every time

 

[kingfish]

Thanks guys, the http://www.gia.edu/reportcheck/ site seems quite useful.