IGI makes it easier to use HCA

[Garry H (Cut Nut)]

I had a note from one of the Directors of IGI

"With reference to some of our conversations and for your information, I just wanted to let you know that we have decided last month to finally implement crown angle as well as pavilion angle on all reports. Both the % and angle will be shown under one field for example CROWN --- 16% - 34.5''. This change will start very soon and is applicable worldwide."

This will be handy for those who want to use https://www.pricescope.com/cutadviser.asp , or the www.facetware.gia.edu also, given that very few stones these days have minor facet combinations that will knock them out.

But there is a growing number of round stones with indexed or cheated girdles around these days - so an ideal-scope image and or DiamCalc Gem Adviser file is still the best way to ensure you have the best looking diamond.

 

[MissAva]

What is a cheated girdle?

 

[Rank Amateur]

Do a search and you''ll get more info than you care to read on cheated girdles and facet indexing.

If I remember correctly, a cheated girdle allows the cutter to retain more weight in the girdle than is apparent from the girdle measurement. These cheated girdles take advantage of the manner by which the lab measures the girdle thickness (thinnest point?) to get a thinner, i.e. better, girdle grade.

 

[Rank Amateur]

By the way, Garry, congratulations in dragging another major lab into the 20th century. Now, on the the 21st...

 

[Kaleigh]

Good for you Garry, it''s about time right??

 

[valeria101]

Btw. finally something positive about IGI around here!

Date: 11/6/2005 8:03:21 PM
Author: Rank Amateur
Do a search and you'll get more info than you care to read on cheated girdles and facet indexing.

If I remember correctly, a cheated girdle allows the cutter to retain more weight in the girdle than is apparent from the girdle measurement. These cheated girdles take advantage of the manner by which the lab measures the girdle thickness (thinnest point?) to get a thinner, i.e. better, girdle grade.

That too, but it also allows that girdle-to-girdle red in the IS pictures of ACA 'new line'

I am not sure of this, but apparently AGS and GIA's top cut grades do not allow too much of it. GIA would disqualify from 'excellent' very thin or thick girdles, and one of the side effects of the cheat is that the girdle outline gets too vary more from thin valleys to thick hills if you wish. There may be other reasons but the girdle thickness for the ban of cheated girdles, but I have no idea about that. I am writing this, hoping to clarify.


The picture show some terrible exagerations - for the sake of making things clear.
Please do correct me if this is wrong, anyone.

Thanks.

 

[MissAva]

Thanks Ana and RA!

 

[belle]

well done garry.

 

[strmrdr]

They going to use sarin or helium?

Now if they could get color and clarity grading right it might be kewl.
I was less than impressed with how the labs director responded on TV when questioned about the bad grading that the study found with igi graded stones.

 

[valeria101]

Date: 11/6/2005 11:32:42 PM
Author: strmrdr

Now if they could get color and clarity grading right it might be kewl.

Apparently IGI started with the mission to provide strict grades (a decade or so ago) and had to tone down for the sake of business sense. I can't remember the source of this the life of me. It sounds reasonable that they match the grading practice of whatever demand there is for their reports.


Aside GIA, doesn't every single lab provide some sort of cut grading report ? At least as an option, even though some types of reports may not contain any mention of these grades.


IGI had a 'ideal cut' label for quite some time. The news must be more information on the lab report to help make sense of it.


Are we supposed to start questioning those measurements too now, like the other good old grades ?

 

[Garry H (Cut Nut)]

without wanting to start WWIII again, I have some stones grade via India and find them to be very good. They are more consistant than GIA on clarity, and from my experiance they are the same. On color they can be about 1/4 of a grade looser on borderline stones (again, in my experiance).

 

[strmrdr]

Date: 11/7/2005 12:52:09 AM
Author: Garry H (Cut Nut)
without wanting to start WWIII again, I have some stones grade via India and find them to be very good. They are more consistant than GIA on clarity, and from my experiance they are the same. On color they can be about 1/4 of a grade looser on borderline stones (again, in my experiance).

that wasnt what dateline i believe it was found.
IGI was worse than any of the various egl labs on grading accuracy and consistancy.

 

[fire&ice]

I have an IGI stone that I bought last year. The stone was graded in 1998. All crown, pavillion angles and degree were in the report. So, they were providing this information with some of their stones already.

 

[anika]

Hi Garry,
Not meaning to hijack your thread but quick question.
I read with interest that you had good experience with grading for stones ex India. Can you tell me if this is IGI Mumbai ( I believe this is IGI''s office in India)? I visit India regularly but never buy any stones (even though they are half the price) because of problems of even getting a cert and IGIs reputation.
Thanks in advance


Anika.

 

[Garry H (Cut Nut)]

Yes Fire and Ice, some types of IGI reports have had angles for a long time.

Date: 11/7/2005 8:37:45 PM
Author: anika
Hi Garry,
Not meaning to hijack your thread but quick question.
I read with interest that you had good experience with grading for stones ex India. Can you tell me if this is IGI Mumbai ( I believe this is IGI''s office in India)? I visit India regularly but never buy any stones (even though they are half the price) because of problems of even getting a cert and IGIs reputation.
Thanks in advance


Anika.

Anika IGI has been operating in India for 30 years and are much better known and respected in the retail market there than any other lab.
I have little experiance with IGI stones from USA - I hear bad things - but then we heard bad things about EGL USA that were not born out when we did a survey.

BTW IGI had a 30th year award evening in India recently. If you are a frequent visitor to India you must have seen this guy who is pictured here with Marc Brauner - Director of the Asian labs.

Bollywood actor, Amitabh Bachchan, was the star in a movie that we saw this year - Black - based loosely on an Indian remake of Helen Keller. It is part Hindi and part English and needs no translation - mainly because the acting is superb. I would recomend this movie to anyone.

 

[anika]

Hi Garry,
Amitabh Bachan does get around. It seems like he is in every Bollywood film and now diamond lab events too. (His nickname is "Big B"). I saw Black BTW; very intense.
Good to know about IGI india. The logistics of grading things ie couriering to Mumbai etc is also something to consider. Thanks

Anika