Why don''t GIA reports list angles?

[rocknovice]

Why don''t GIA reports list the angles of the diamond? In order to list the percentages that they do, dont they have to get a sarin report? The only reason I can think of is to make it more difficult for consumers to make an educated purchase.

A diamond is what it is. The GIA report is supposedly telling you what it is. I can''t believe the people at GIA think angles are an unimportant criteria when chosing a diamond. Maybe they havent agreed on how to interpret them based on their lack of a cut grade, but I''ll bet every GIA certified gemologist that buys a diamond for his/her own use checks the angles.

Isnt a sarin report pretty inexpensive? Isnt it dont during the GIA grading process? Any comments?

 

[Garry H (Cut Nut)]

GIA use sarin and they have the data.
They will give it to the person who submitted the stone to the lab.

Masybe they dont have enough space on the reports

 

[lacina]

Great question!
GIA does educate about the importance of a cut and it's effect on value of a diamond they believe the cut of RB is another issue by it self. The lab is known for it's concistency in grading of diamonds for more than 50 years in business. This means the early generation GIA Grading Reports are still being recognized as valid. There was no more information needed to be disclosed at that time and therefore the new generation reports list pretty much the same info as the previous versions. I have heard that GIA is considering to add this service
in the future , however I don't know if this will hurt the validity of the old GIA reports . I suspect this can be an issue ,...

I like the way GIA builts their name and I would swear by their grading my self,... It is known that GIA does not certify diamonds or issues an appraisals nor reccommands witch diamond the consumer should buy. Never issues an Ideal grade nor poor grade in cut grading,.. However GIA EX/EX make stones are hard to find!,...
I personaly think that GIA certs can stay the way they are since they are easy to read and accurate enough for any type of buyer.
Cut specialists and Ideal cut hunters should use AGS reports at this time.

Best
George

 

[Garry H (Cut Nut)]

So Lacina you are happy with AGS cut grading?
You like diamonds with >35 crown angles and >41 degree pavilions?

 

[rocknovice]

The reason I asked about the GIA reports not having the angles listed is because I find I difficult to get them from retailers. When I ask, they want to know why I want them. Usually there is no sarin report available. Based on what I see on the net, I am surprised how many retailers in Chicago have never heard of HCA.

I recently met with a manufacturer that says he has over 700 stones being graded. He claims to have never heard of HCA but was interested when I talked about it. He did have very large number of AGS0 stones available to look at but I found it difficult to decide what to do because I didnt feel that I could judge a good AGS0 from a bad one without getting a copy of the cert to get the HCA number from it. Because he wasnt familiar with HCA, I couldnt expect him to determine the number for me. He also said that if a stone has a cut grade of AGS0 then that's all that matters, it is ideal. He didnt think there was any differnce between them.

Is there a range of angles that I could use as a guideline to narrow a stone down to an HCA less than 2? I found a AGS0 E SI1 that I thought might be ok but when I ran the numbers it was a 2.7.

Thanks.

 

[Garry H (Cut Nut)]

<35 and <40.8 should be safe

 

[MDE]

Rock novice

I recently, after a 1year search purchased a 1.0 crt D. FL . I found the HCA a wonderful tool to sort out the good from the bad when assessing proportion.

Very early in my search I was forced to totally disregard GIA certificates, as I could not rely on guessing the crown height or crown and pavilion angles to input the HCA.

A jeweller told me it was possible to calculate the angles or crown height from the data on the GIA certificate, but was unable to demonstrate it.

I then only looked at AGS data, totally disregarding their grading and ended up with an excellent stone that scored 0.1. I think it could be called a Hearts and Arrows, as they are very distinct, looking through one of those scope things.

The dimensions are

Total Height: 58.6%
Crown Height: 14.2
Pavilion Depth: 42.2
Girdle: 2.2:


Based on my experience I must conclude that it seems to be impossible to assess the possible cut quality of a GIA certified stone without seeing it.

Harry

 

[trichrome]

Usually, when crown angles are over 35o, it will be written in the comment section
of the GIA certificate (dossier or anything else) that "warning, crown angles are
over 35o". However, what I don't know if this applies to old certs as well? Garry or anyone
else might have more info on that.

Best regards,

Trichrome.

 

[diamondsman]

The G.I.A will only show on thier certs if the stones ahve crown angeles less than 30% or more than 35% the first one being a shallow stone, and the second one being a bit on the heavy made side.
a diamond dealer would usually know (on rounds) if the stone it up to par, by the measurements, depth, table,etc...
(all the spects. of the cert.)
without using a sarin machine.
I know I have been doing it for the last 30 years.

diamondsman