Letter to the Editor of the Australian Gemmologist

[adamasgem]

Date: 3/1/2007 6:38:30 AM
Author: DiaGem

And I would be surprised to hear that GIA grades Fancy-Colored Diamonds on DD, especialy when these Diamonds are only graded faced-up!!!!!!!!

Is the above a question or statement????

All G&G articles refer to the Judge II Booth for grading fancy color..

 

[adamasgem]

Date: 3/1/2007 6:38:30 AM
Author: DiaGem
And now for the bad news (unless i am used to my own lighting environment), I think it is definitely the wrong tool-box to determine/grade a color for D-Z graded colored Diamonds. I may be wrong..., but that is what i picked up after a rather quick test!!!!

I haven''t seen the bulbs yet for the KittyDock(TM), but undestand they have a new bulb manufacturer somewhere in Florida..

Along with a possible different spectra than the fluorescents used in the old DiamondLite and/or your office fluorescenct desk lap, will cause a mettamerism effect, varying with the type of stabilization doping in CZ''s. CZ''s are doped (to crystalize in the cubic system) with large % of Yttrium (a rare earth) or with Calcium.

The spectra of Calcium doped CZ''s is not too bad relative to type Ib or IIa absorption, but is entirely unlike the cape series, except in a global sense..

Rare earth doped CZ''s will probably shift more when you start dicking around with the light source, and if, what is entirely possible, given the limited CZ sets I have seen, is that the CZ''s types are mixed in the sets, some Calcium doped and some Yttrium doped. They are also not stable to UV and can, I believe, permanently shift color.

I KNOW that they (CZ''s) get really permanently shifted when exposed to electron beams like what was used to sterilize the mails following 9/11.

Diamonds also permanently shift color (although very little) with the low dose E Beam used to sterilize mails from Anthrax, visible with spectroscopy as the start of broad band GR1 damage.

I did these tests at TitanScan in 2001, thanks to support and contributions from AGS and Dave Atlas, and commentary was published in JCK.

GIA, of course, disagreed, because their tests relied on color memory... (But they have a long history of disagreeing, and then never admitting they were wrong.)

 

[Serg]

Date: 3/1/2007 3:07:26 AM
Author: Garry H (Cut Nut)

Date: 2/28/2007 1:21:56 PM
Author: strmrdr

1st: DD stuff is a red herring. The DD isnt in my opinion why the system is bad.

Storm I have had a small window of opportunity to do some testing inside Diamond Dock.

I used 2 princess cuts chosen at random and one shallow ish round that I happened to have with me.

The photo''s on the top row have the fluoro only lights on and are taken at about 40 - 45 dgerees between the stones and the light center point (the viewing angle that I believe was used in the GIA survey to set the proportion grades).

I think you would agree that had I found better examples of princess cuts (I had already bought the best ones and they were packed away) then this grading environment would favour princess cuts over rounds. i.e. princess cuts would be morre ideal than ideal cut rounds!

The lower photo''s are a bit fuzzy because they were taken with the lights off and I had some camera shake because the exposure time was longer.
In fact you very clearly see the round stone is far brighter with just the ambient room light - and this is the normal situation.

I fail to see how a grading environment that gets such a fundemental difference wrong can be used as the basis of a multi billion dollar decision making process.

Is this a red herring?

Good shot

 

[adamasgem]

Date: 3/1/2007 2:26:45 PM
Author: Serg

Date: 3/1/2007 3:07:26 AM
Author: Garry H (Cut Nut)

Date: 2/28/2007 1:21:56 PM
Author: strmrdr

1st: DD stuff is a red herring. The DD isnt in my opinion why the system is bad.

Storm I have had a small window of opportunity to do some testing inside Diamond Dock.

I used 2 princess cuts chosen at random and one shallow ish round that I happened to have with me.

The photo''s on the top row have the fluoro only lights on and are taken at about 40 - 45 dgerees between the stones and the light center point (the viewing angle that I believe was used in the GIA survey to set the proportion grades).

I think you would agree that had I found better examples of princess cuts (I had already bought the best ones and they were packed away) then this grading environment would favour princess cuts over rounds. i.e. princess cuts would be morre ideal than ideal cut rounds!

The lower photo''s are a bit fuzzy because they were taken with the lights off and I had some camera shake because the exposure time was longer.
In fact you very clearly see the round stone is far brighter with just the ambient room light - and this is the normal situation.

I fail to see how a grading environment that gets such a fundemental difference wrong can be used as the basis of a multi billion dollar decision making process.

Is this a red herring?

Good shot

Serg: What is even more interesting is the relationship between the KittyDock(TM) environment and the environments they say they used for judging Brilliance and Fire.

Modeling the variable KittyDock(TM) environment is a bitch..

Have you done that type of superb reverse raytrace projection of the KittyDock(TM) environment, like you showed us at the AGS conclave?

That was absolutely awesome work

Have you made a movie file that you could share with PS readers..

I''m really looking foreward to that software release, although I guess I''ll have to get a dual core processor Laptop to use that, it will be worth it.

 

[diagem]

Date: 3/1/2007 12:26:56 PM
Author: adamasgem

Date: 3/1/2007 6:38:30 AM
Author: DiaGem

And I would be surprised to hear that GIA grades Fancy-Colored Diamonds on DD, especialy when these Diamonds are only graded faced-up!!!!!!!!

Is the above a question or statement????

All G&G articles refer to the Judge II Booth for grading fancy color..

I am sorry..., but I am not familiarised with this, can you elaborate?

 

[strmrdr]

Garry,
The GIA system would have sucked even if they paid Serg and Marty to design and bless the light box due to the other problems.
So yes its a red herring.

 

[adamasgem]

Date: 3/1/2007 3:51:28 PM
Author: DiaGem

Date: 3/1/2007 12:26:56 PM
Author: adamasgem

Date: 3/1/2007 6:38:30 AM
Author: DiaGem

And I would be surprised to hear that GIA grades Fancy-Colored Diamonds on DD, especialy when these Diamonds are only graded faced-up!!!!!!!!

Is the above a question or statement????

All G&G articles refer to the Judge II Booth for grading fancy color..

I am sorry..., but I am not familiarised with this, can you elaborate?

Macbeth Munsell JudgeII grading booth..

http://www.rpimaging.com/store/PID46

If you want to know about the Fancy Color Diamonds, GIA Gems and Gemology has published a reprint of G&G articles dealing with grading and determination of fancy colored diamonds and their system using Munsell chip set.

http://www.gia.edu/gemsandgemology/33977/colored_diamonds_book.cfm

IT IS A GREAT buy at about $60.00. Hats off to Alice Keller and G&G

 

[diagem]

Date: 3/1/2007 8:11:39 PM

style="WIDTH: 49.72%; HEIGHT: 1px">

Author: adamasgem
Macbeth Munsell JudgeII grading booth..

http://www.rpimaging.com/store/PID46

If you want to know about the Fancy Color Diamonds, GIA Gems and Gemology has published a reprint of G&G articles dealing with grading and determination of fancy colored diamonds and their system using Munsell chip set.

http://www.gia.edu/gemsandgemology/33977/colored_diamonds_book.cfm

IT IS A GREAT buy at about $60.00. Hats off to Alice Keller and G&G

Thanks AG...

I will have some extra questions later if its ok with you...

 

[adamasgem]

Date: 3/2/2007 1:26:16 AM
Author: DiaGem
Thanks AG...

I will have some extra questions later if its ok with you...

No problem...

 

[adamasgem]

Date: 3/1/2007 5:27:00 PM
Author: strmrdr
Garry,
The GIA system would have sucked even if they paid Serg and Marty to design and bless the light box due to the other problems.
So yes its a red herring.

You are right storm.. You need a reproducable envirionment system, which the KittyDock(TM) cannot provide.

The only way to do it right is by raytrace. GIA started on the right foot, missed the boat on the uniform illumination, did some good work with observation studies with multi segmented domes, and then dropped the boat when they tried to correlate results with another envirionmennt..

The whole thing can''t be parametric, you have to look at the stone as a whole, and analyse it in a consistent envirionment or process...

 

[diagem]

Date: 3/1/2007 12:50:33 PM
Author: adamasgem
I did these tests at TitanScan in 2001, thanks to support and contributions from AGS and Dave Atlas, and commentary was published in JCK.

GIA, of course, disagreed, because their tests relied on color memory... (But they have a long history of disagreeing, and then never admitting they were wrong.)

I am under the assumption that all devises that issue color grades on D-Z range Diamonds are based on "substance/color memory".

 

[diagem]

style="WIDTH: 97.69%; HEIGHT: 194px">Macbeth Munsell JudgeII grading booth..

http://www.rpimaging.com/store/PID46

If you want to know about the Fancy Color Diamonds, GIA Gems and Gemology has published a reprint of G&G articles dealing with grading and determination of fancy colored diamonds and their system using Munsell chip set.

http://www.gia.edu/gemsandgemology/33977/colored_diamonds_book.cfm

IT IS A GREAT buy at about $60.00. Hats off to Alice Keller and G&G

AG,

Is the Macbeth Munsell JudgeII grading booth a common practice with Fancy Colored Diamond manufacturers?
What imakes it better suitable to visualize Color in Diamonds vs. ordinary daylight or Diamond office environment??
Is it suitable for Precious Colored GemStones?

 

[Garry H (Cut Nut)]

Date: 3/2/2007 7:46:22 AM
Author: DiaGem

style="WIDTH: 97.69%; HEIGHT: 194px">Macbeth Munsell JudgeII grading booth..

http://www.rpimaging.com/store/PID46

If you want to know about the Fancy Color Diamonds, GIA Gems and Gemology has published a reprint of G&G articles dealing with grading and determination of fancy colored diamonds and their system using Munsell chip set.

http://www.gia.edu/gemsandgemology/33977/colored_diamonds_book.cfm

IT IS A GREAT buy at about $60.00. Hats off to Alice Keller and G&G

AG,

Is the Macbeth Munsell JudgeII grading booth a common practice with Fancy Colored Diamond manufacturers?
What imakes it better suitable to visualize Color in Diamonds vs. ordinary daylight or Diamond office environment??
Is it suitable for Precious Colored GemStones?

It is a popular lighting type - but only because it is consistent - but the system sstill uses human graders.

A digital format has been designed by Sergey and Yuri using a variant of diamCalc - the little dots are the individual parts of color in this image on the left - dark are on the left and brightest - some people call this a colored gems ''DNA''.

The curved white lines on the lower right chart show the GIA Fancy yellow grade borders that they have been able to digitally position based on a 10 year old Gems & Gemology article.

The software can take a spectra of the stone and design the best cut for the right Chroma and Contrast to make the best Fancy Vivid or Intense color grade from GIA.

 

[adamasgem]

Date: 3/2/2007 7:31:21 AM
Author: DiaGem

Date: 3/1/2007 12:50:33 PM
Author: adamasgem
I did these tests at TitanScan in 2001, thanks to support and contributions from AGS and Dave Atlas, and commentary was published in JCK.

GIA, of course, disagreed, because their tests relied on color memory... (But they have a long history of disagreeing, and then never admitting they were wrong.)

I am under the assumption that all devises that issue color grades on D-Z range Diamonds are based on ''substance/color memory''.

Devices, like my SAS2000, can record the underlying technical data

GIA did visual color checks, pre/post irradiation, to my knowledge, and stomped their heavy feet really bad in Tuscon, that there was no "perceptible color change" when I challanged them on it at a presentation they were making. (I guess that was so, if you were wearing horse blinders)

http://www.jckonline.com/article/CA197404.html

I presented the change in spectra for a round trip through the mail (~ 13 MegaRad from 10 Mev Electrons), showed small color grade changes, maybe 5% of a color grade, due to the onset of broadband GR1 damage.
A cummulative effect, next time, it would increase.

I believe, this type of thing may be stilll be only being done for Congressional/Presidential mail, but I''m not sure. I was told yesterday by TitanScan, that there was some facility, not operated by them, someplace in NJ.

 

[adamasgem]

Date: 3/2/2007 7:46:22 AM
Author: DiaGem

style="WIDTH: 97.69%; HEIGHT: 194px">Macbeth Munsell JudgeII grading booth..

http://www.rpimaging.com/store/PID46

If you want to know about the Fancy Color Diamonds, GIA Gems and Gemology has published a reprint of G&G articles dealing with grading and determination of fancy colored diamonds and their system using Munsell chip set.

http://www.gia.edu/gemsandgemology/33977/colored_diamonds_book.cfm

IT IS A GREAT buy at about $60.00. Hats off to Alice Keller and G&G

AG,

Is the Macbeth Munsell JudgeII grading booth a common practice with Fancy Colored Diamond manufacturers?
What imakes it better suitable to visualize Color in Diamonds vs. ordinary daylight or Diamond office environment??
Is it suitable for Precious Colored GemStones?

It is a standardized grading evironment for labs grading fancy colors, that is for sure, and I know of at least one fancy colored diamond dealer who uses it. And it is a standard for many industries.

What was surprizing at the time when GIA came out with their new fancy colored grading system, that they never offered it for sale at Gem Instruments.

And it appears cheaper than the KittyDock(TM).

Currently, AGS uses the Judge II booth with D6500K illumination for colorless diamonds.

 

[adamasgem]

''

Date: 3/2/2007 9:47:18 AM
Author: Garry H (Cut Nut)

It is a popular lighting type - but only because it is consistent - but the system sstill uses human graders.

Rumour has it, that GIA uses "instrumentation", possibly based on their patent for reflectance measurement colorimetry, on larger colorless diamonds. My sources tell me that this was recently revealed to the DDC board, and that GIA might have been doing this for some time without informing the industry. I cannot confirm this.

 

[adamasgem]

Date: 3/2/2007 12:37:24 PM
Author: adamasgem
''

Date: 3/2/2007 9:47:18 AM
Author: Garry H (Cut Nut)

It is a popular lighting type - but only because it is consistent - but the system sstill uses human graders.

Rumour has it, that GIA uses ''instrumentation'', possibly based on their patent for reflectance measurement colorimetry, on larger colorless diamonds. My sources tell me that this was recently revealed to the DDC board, and that GIA might have been doing this for some time without informing the industry. I cannot confirm this.

I have gotten one "no comment" so far, from a high ranker there, who should know.

 

[diagem]

Date: 3/2/2007 12:17:05 PM
Author: adamasgem

It is a standardized grading evironment for labs grading fancy colors, that is for sure, and I know of at least one fancy colored diamond dealer who uses it. And it is a standard for many industries.

What was surprizing at the time when GIA came out with their new fancy colored grading system, that they never offered it for sale at Gem Instruments.

And it appears cheaper than the KittyDock(TM).

Currently, AGS uses the Judge II booth with D6500K illumination for colorless diamonds.

That is so weird, I used to be involved in designing and cutting fancy colored Diamonds about 7-8 years ago...
But these days I personally know some major players in the "fancy colored Diamond" cutting/manufacturers niche..., and i don''t think any of them use this booth..., or in fact even know of its existence!!!

If it is so good for colored Diamonds..., why would players that cut multi-million Dollars of extremely high quality colored Diamonds not even know about it ????

Weird!!!

 

[diagem]

Date: 3/2/2007 12:37:24 PM
Author: adamasgem
''

Date: 3/2/2007 9:47:18 AM
Author: Garry H (Cut Nut)

It is a popular lighting type - but only because it is consistent - but the system sstill uses human graders.

Rumour has it, that GIA uses ''instrumentation'', possibly based on their patent for reflectance measurement colorimetry, on larger colorless diamonds. My sources tell me that this was recently revealed to the DDC board, and that GIA might have been doing this for some time without informing the industry. I cannot confirm this.

Do you mean "devices"?
If you do...., I am with you on that...
I dont know for a fact, but i did notice that some Rough Diamonds I use show off some color in its rough state, (like H-I-J), and as a finished polished Diamond are up-graded by me/my staff colorless (G+). BUT, after having it graded by GIA it returns with a H-I-J color-grading!!!

That is what made me suspect that GIA is using color-devices!!!

Am I making sense???

 

[padparashah]

Dear Gary,

I have a GIA cert which is graded Excellent in Cut as well as Polish and symmetry.

Its 59% table 62.2% depth 41.0 pavilion angle and 35.5 crown angle.

The HCA you have created only returned a Good on all grades .

I am not sure what to comment .

Is GIA standards Flawed or The HCA is Flawed .

Thank you for your reply.

warmest regards , dave

 

[Garry H (Cut Nut)]

Date: 3/3/2007 4:09:55 AM
Author: padparashah
Dear Gary,

I have a GIA cert which is graded Excellent in Cut as well as Polish and symmetry.

Its 59% table 62.2% depth 41.0 pavilion angle and 35.5 crown angle.

The HCA you have created only returned a Good on all grades .

I am not sure what to comment .

Is GIA standards Flawed or The HCA is Flawed .

Thank you for your reply.

warmest regards , dave

Pad read the article linked from the first page and make your own conclusions.
We are dissapointed with GIA''s grading system.

But HCA needs to be re thought because it is a mono (single eyed) based. Two eyes do not see as much table leakage as one - so your stone should be around HCA 2-2.5 and not 4 ish because of that reason.

A stone like yours can benefit from a little painting (another big hot topic here abouts) from my experiance. Perhaps it is?

 

[adamasgem]

Date: 3/3/2007 2:05:44 AM
Author: DiaGem

Date: 3/2/2007 12:37:24 PM
Author: adamasgem
''

Date: 3/2/2007 9:47:18 AM
Author: Garry H (Cut Nut)

It is a popular lighting type - but only because it is consistent - but the system sstill uses human graders.

Rumour has it, that GIA uses ''instrumentation'', possibly based on their patent for reflectance measurement colorimetry, on larger colorless diamonds. My sources tell me that this was recently revealed to the DDC board, and that GIA might have been doing this for some time without informing the industry. I cannot confirm this.

Do you mean ''devices''? Yup
If you do...., I am with you on that...
I dont know for a fact, but i did notice that some Rough Diamonds I use show off some color in its rough state, (like H-I-J), and as a finished polished Diamond are up-graded by me/my staff colorless (G+). BUT, after having it graded by GIA it returns with a H-I-J color-grading!!!

That is what made me suspect that GIA is using color-devices!!!

Am I making sense???

What size stones are you dealing with?????

This aspect of discussion is best left to private communication, go to my web site and send me an email and we can communicate by phone..

 

[diagem]

Date: 3/3/2007 7:05:24 AM
Author: adamasgem

Date: 3/3/2007 2:05:44 AM
Author: DiaGem

Date: 3/2/2007 12:37:24 PM
Author: adamasgem
''

Date: 3/2/2007 9:47:18 AM
Author: Garry H (Cut Nut)

It is a popular lighting type - but only because it is consistent - but the system sstill uses human graders.

Rumour has it, that GIA uses ''instrumentation'', possibly based on their patent for reflectance measurement colorimetry, on larger colorless diamonds. My sources tell me that this was recently revealed to the DDC board, and that GIA might have been doing this for some time without informing the industry. I cannot confirm this.

Do you mean ''devices''? Yup
If you do...., I am with you on that...
I dont know for a fact, but i did notice that some Rough Diamonds I use show off some color in its rough state, (like H-I-J), and as a finished polished Diamond are up-graded by me/my staff colorless (G+). BUT, after having it graded by GIA it returns with a H-I-J color-grading!!!

That is what made me suspect that GIA is using color-devices!!!

Am I making sense???

What size stones are you dealing with?????

This aspect of discussion is best left to private communication, go to my web site and send me an email and we can communicate by phone..

the whole range...

Please dont take this the wrong way..., but right now I prefer to stay anonymous on this open/public PS forum.

But it is very interesting if they (GIA) do...
I will do homework on my side...

Thanks

 

[adamasgem]

Date: 3/3/2007 4:09:55 AM
Author: padparashah
Dear Gary,

I have a GIA cert which is graded Excellent in Cut as well as Polish and symmetry.

Its 59% table 62.2% depth 41.0 pavilion angle and 35.5 crown angle.

The HCA you have created only returned a Good on all grades .

I am not sure what to comment .

Is GIA standards Flawed or The HCA is Flawed .

Thank you for your reply.

warmest regards , dave

Dave.. I''m going to use a International Free Pistol analogy (which I used to compete in) to give you qualitative comment..

The indoor 50ft 10 ring is the diameter of about a 22 caliber round, about the size of your pupil... so you basically have to be within 2 diameters to clip the ten ring and register a 10,

Obviously the chance of clipping the 10 ring (in this case getting the "wrong" answer by "cheating") depends on the size of the bullet, or the number of shot in the round

All other factors being equal, parametrically based systems based on averaged parameters, will give you a higher score, but because they use the big bore approach (averaged parameters), and what is reported is the score, you never see the size of the holes in the actual target..

In my opinion:

GIA is using a 50 caliber..

HCA is probably shooting a 45 caliber..

Systems using actual, non averaged measurements, are currently shooting with anywhere from a 38 to 32 caliber bullets, no one will ever be able to use the correct 22 caliber bullet because of inherent measurement limitations, and lack of knowledge of the correlations between the measurements they are given. At best, eventually, they might be given a 25 caliber to use. I seriously doubt that they will ever be given, by the equipment manfacturers, a 22 caliber Hammerlli to use..

Now we come to the target being used, the size of the bullseye they are using, the Metric, which is subject to a lot of discussion and controvsey in most cases..

GIA seems to be using a shotgun patterning target...

The rest are currently using center fire targets (much larger ten ring) and are probably shooting at 30 to 40 feet right now..

We will probably never agree on the target size such that it is equiviilant to a free pistol target, and at best, might get to the size of 22 caliber gallary match rapid fire target 10 ring.

Confused yet???

 

[padparashah]

Date: 3/3/2007 5:22:50 AM
Author: Garry H (Cut Nut)

Date: 3/3/2007 4:09:55 AM
Author: padparashah
Dear Gary,

I have a GIA cert which is graded Excellent in Cut as well as Polish and symmetry.

Its 59% table 62.2% depth 41.0 pavilion angle and 35.5 crown angle.

The HCA you have created only returned a Good on all grades .

I am not sure what to comment .

Is GIA standards Flawed or The HCA is Flawed .

Thank you for your reply.

warmest regards , dave

Pad read the article linked from the first page and make your own conclusions.
We are dissapointed with GIA''s grading system.

But HCA needs to be re thought because it is a mono (single eyed) based. Two eyes do not see as much table leakage as one - so your stone should be around HCA 2-2.5 and not 4 ish because of that reason.

A stone like yours can benefit from a little painting (another big hot topic here abouts) from my experiance. Perhaps it is?

Dear Garry ,

What do you mean by painting ? I dont get you on this , pls explain .

Thank you for being honest about the HCA needing a serious rethink, In fact for accuracy sake and the benefit of the millions who might have tried the HCA , you should pull out the HCA . What purpose does it serve if it is not accurate ?

I have tried my level best to go through every article , It seems the GIA has come in for alot of criticism.
Some Criticism i feel are personal and done more so because of jealousy.

I Graduated from GIA Headquarters in 2004. I have seen Boyaigian and the whole gang .
Its True , i have my share of criticism as well . I didnt like Boyaigian in the sense that he made everything so expensive
at GIA. It didnt seem non profit to me .
There''s also this dropping of standards for the GG diploma. My Mum and Dad are GG''s as well, and they told me the graduates of yesteryears are much stronger and had to work harder to earn the diploma.
And quite sadly i learned that Distance students who earn the same title of GG had an easier Final Exam then the resident students .As such i felt like me flying all the way to USA was in a sense at first , a waste of money when i can just earn it easily in the comforts of my own home.
And i wasnt surprised when Boyaigian was involved in that scandal and had to quit . I was happy that he left .

Thinking through it all, i think GIA is very smart . Spurring on more people to know more about gemology encourages the power of knowledge to be shared with consumers. That was the main priority.
And GIA understands that you dont have to be an outstanding GG graduate to succeed in the jewelry industry. Because even if you are not a GG , you can be as successful or even more. As such the relaxation of standards to meet the current generation. However , if you wanted to be a great graduate , they had everything for you to be one.Outstanding Lecturers , Fantastic facilities second to none.
The minimum as a GG was that you had to be strong on fundamentals and GIA knows that a GG is really just a starting pt.
And regarding the high fees .... i think well , If it really goes back into research ...i am ok with that. Besides on campus, you really meet alot of people , children of sightholders , you see them all at GIA. You get great Network there.

I am not a very scientific person as any of you here . I think from what i have read , you guys are very smart with all your interesting analysis. I salute you guys for putting in so much creativity and passion .
But i want to say that i would only agree that GIA standards like the Excellent Cut grade is perhaps , it seems statistically , not as strict as the AGS . And the 17 Rbc comparison is not a fair guage as its not enough to assure consistency.
But i feel GIA understands practical wisdom.

So what if you have 11 grades , can you really see the difference between each grade . ? with the naked eye.
I think 5 grades seems more practical , more able to discern easier for the consumer.
For Excellent Cut GIA, i havent come across outrageous proportions as GIA has been accused of .
At the most are 59% tables and 62.5% total depths ....i havent seen a stone with 63% depth ...

The persuit of the greatest CUT is perhaps only worth it if you really can see the difference for sure .
If its just 1 or 2 facet more light return , is it worth to debate over such small differences ?
Can the consumers really see the difference ? Even as a trained professional , i find it not easy to discern when comparing the top cuts ....
And are consumers having their throats cut because of All these marketing of AGS triple 0 and etc ....paying so much much more ......does it justify that they pay so much more for just that little little bit of difference ???
I personally dont think its worth it ....
I still have much faith with the GIA cut grading . I do not think that they need to pull it out .

Thank you for reading and my apologies if i veered off the main topic a little
I suppose i will be getting some very stinging criticism for this letter ....
ha ha ....but its ok because i feel like family with you fellas talking about diamonds ....haha ....
I wont be upset ....i hope to learn something in fact .....pls correct me if i seemed ignorant....


warmest regards, dave

 

[Garry H (Cut Nut)]

Date: 3/3/2007 10:14:17 AM
Author: padparashah

Date: 3/3/2007 5:22:50 AM
Author: Garry H (Cut Nut)

Date: 3/3/2007 4:09:55 AM
Author: padparashah
Dear Gary,

I have a GIA cert which is graded Excellent in Cut as well as Polish and symmetry.

Its 59% table 62.2% depth 41.0 pavilion angle and 35.5 crown angle.

The HCA you have created only returned a Good on all grades .

I am not sure what to comment .

Is GIA standards Flawed or The HCA is Flawed .

Thank you for your reply.

warmest regards , dave

Pad read the article linked from the first page and make your own conclusions.
We are dissapointed with GIA's grading system.

But HCA needs to be re thought because it is a mono (single eyed) based. Two eyes do not see as much table leakage as one - so your stone should be around HCA 2-2.5 and not 4 ish because of that reason.

A stone like yours can benefit from a little painting (another big hot topic here abouts) from my experiance. Perhaps it is?

Dear Garry ,

What do you mean by painting ? I dont get you on this , pls explain .

Thank you for being honest about the HCA needing a serious rethink, In fact for accuracy sake and the benefit of the millions who might have tried the HCA , you should pull out the HCA . What purpose does it serve if it is not accurate ?

I have tried my level best to go through every article , It seems the GIA has come in for alot of criticism.
Some Criticism i feel are personal and done more so because of jealousy.

I Graduated from GIA Headquarters in 2004. I have seen Boyaigian and the whole gang .
Its True , i have my share of criticism as well . I didnt like Boyaigian in the sense that he made everything so expensive
at GIA. It didnt seem non profit to me .
There's also this dropping of standards for the GG diploma. My Mum and Dad are GG's as well, and they told me the graduates of yesteryears are much stronger and had to work harder to earn the diploma.
And quite sadly i learned that Distance students who earn the same title of GG had an easier Final Exam then the resident students .As such i felt like me flying all the way to USA was in a sense at first , a waste of money when i can just earn it easily in the comforts of my own home.
And i wasnt surprised when Boyaigian was involved in that scandal and had to quit . I was happy that he left .

Thinking through it all, i think GIA is very smart . Spurring on more people to know more about gemology encourages the power of knowledge to be shared with consumers. That was the main priority.
And GIA understands that you dont have to be an outstanding GG graduate to succeed in the jewelry industry. Because even if you are not a GG , you can be as successful or even more. As such the relaxation of standards to meet the current generation. However , if you wanted to be a great graduate , they had everything for you to be one.Outstanding Lecturers , Fantastic facilities second to none.
The minimum as a GG was that you had to be strong on fundamentals and GIA knows that a GG is really just a starting pt.
And regarding the high fees .... i think well , If it really goes back into research ...i am ok with that. Besides on campus, you really meet alot of people , children of sightholders , you see them all at GIA. You get great Network there.

I am not a very scientific person as any of you here . I think from what i have read , you guys are very smart with all your interesting analysis. I salute you guys for putting in so much creativity and passion .
But i want to say that i would only agree that GIA standards like the Excellent Cut grade is perhaps , it seems statistically , not as strict as the AGS . And the 17 Rbc comparison is not a fair guage as its not enough to assure consistency.
But i feel GIA understands practical wisdom.

So what if you have 11 grades , can you really see the difference between each grade . ? with the naked eye.
I think 5 grades seems more practical , more able to discern easier for the consumer.
For Excellent Cut GIA, i havent come across outrageous proportions as GIA has been accused of .
At the most are 59% tables and 62.5% total depths ....i havent seen a stone with 63% depth ...

The persuit of the greatest CUT is perhaps only worth it if you really can see the difference for sure .
If its just 1 or 2 facet more light return , is it worth to debate over such small differences ?
Can the consumers really see the difference ? Even as a trained professional , i find it not easy to discern when comparing the top cuts ....
And are consumers having their throats cut because of All these marketing of AGS triple 0 and etc ....paying so much much more ......does it justify that they pay so much more for just that little little bit of difference ???
I personally dont think its worth it ....
I still have much faith with the GIA cut grading . I do not think that they need to pull it out .

Thank you for reading and my apologies if i veered off the main topic a little
I suppose i will be getting some very stinging criticism for this letter ....
ha ha ....but its ok because i feel like family with you fellas talking about diamonds ....haha ....
I wont be upset ....i hope to learn something in fact .....pls correct me if i seemed ignorant....


warmest regards, dave

Pad Dave - Marty will join you in the anti Bill B discussion. Personally he was great - i would love to have someone like him running my Company - and GIA is a Company, it just happens to be one that can pay no tax. And they do a lot of good. But Yin and Yang - they unintentionally do bad too, like most lumbering giants.

HCA is a screening tool, and it is tough on vendors because it gives my (old) opinion. but the format could work in a new way. But it is very likely that you will get a nice dianmond if you use it wisely.

I think I need to change the idea of a recomendation. It should just give information. and this can be done. But until I can trust the information (it has my name in it) I can not really change it. I am working on that - but the solution is non obvious. As Marty once said to me, think hard. He did not know that I think hard. He should think hard too as he reads this, and try to understand what I mean.

AGS and GIA try to simplify very complex things. They also rule out many great diamonds - and most diamonds that can be good at some things in some lighting - visa-v- Calendarha's olde cut with huge flashes of fire -see the Fire thread. It probably would rate a AGS 7 and GIA Good. (Fair-Good in GIA terms = lowest 35% according to Bill B's comments in India 2 years ago).

Finally let me compliment you. Rarely does someone emerge from GIA training and still have their own unbrainwashed sense. (edit Last sentance removed)

 

[adamasgem]

Date: 3/3/2007 11:27:57 AM
Author: Garry H (Cut Nut)

Pad Dave - Marty will join you in the anti Bill B discussion. Personally he was great - i would love to have someone like him running my Company - and GIA is a Company, it just happens to be one that can pay no tax. And they do a lot of good. But Yin and Yang - they unintentionally do bad too, like most lumbering giants.

Our personal experiances with Beetlejuice are quite different..

HCA is a screening tool, and it is tough on vendors because it gives my (old) opinion. but the format could work in a new way. But it is very likely that you will get a nice dianmond if you use it wisely.

You are inherently limited with parametric systems, I think you have probably done a better job with HCA from a scientific basis than FarceWare(TM).

I think I need to change the idea of a recomendation. It should just give information. and this can be done. But until I can trust the information (it has my name in it) I can not really change it. I am working on that - but the solution is non obvious. As Marty once said to me, think hard. He did not know that I think hard. He should think hard too as he reads this, and try to understand what I mean. I understand you. I think in the instance you are thinking of, I was pulling your chain a little, intentionally. You wanted the answers that were going to make you money, and said I was available as a consultant, expecting to get paid for the answers.

AGS and GIA try to simplify very complex things. (don''t leave HCA or others out of that statement)

They also rule out many great diamonds - and most diamonds that can be good at some things in some lighting - visa-v- Calendarha''s olde cut with huge flashes of fire -see the Fire thread. It probably would rate a AGS 7 and GIA Good. (Fair-Good in GIA terms = lowest 35% according to Bill B''s comments in India 2 years ago). I agree that the tradeoff issues haven''t been adequatly explained, or maybe factored in, in someof the systems.

Finally let me compliment you. Rarely does someone emerge from GIA training and still have their own unbrainwashed sense. (edit Last sentance removed)

Gary, I agree with you 100% there. David seems to have his head on straight, and his Mum and Dad are also correct when it comes to the basics.

There is a new knowledge base that new GG''s hopefully learn, but it is a continuing process for everyone, Although it seems that most GG''s just stop the learning. What percentage get or read G&G, and even fewer, the more technical literature.

Every day there is a new wrinkle upsetting the labs and the trade in general, especially with treatments.

 

[strmrdr]

Date: 3/3/2007 1:03:36 PM
Author: adamasgem

There is a new knowledge base that new GG''s hopefully learn, but it is a continuing process for everyone, Although it seems that most GG''s just stop the learning. What percentage get or read G&G, and even fewer, the more technical literature.

That is a huge issue that myself and a lot of consumers run into.
GG''s that stopped learning 20 years ago and get very grouchy if questioned.

As for the lowered standards that is the trend in education in the US all over not just GIA.

 

[strmrdr]

Date: 3/3/2007 11:27:57 AM
Author: Garry H (Cut Nut)

HCA is a screening tool, and it is tough on vendors because it gives my (old) opinion. but the format could work in a new way. But it is very likely that you will get a nice dianmond if you use it wisely.

I think I need to change the idea of a recommendation. It should just give information. and this can be done. But until I can trust the information (it has my name in it) I can not really change it. I am working on that - but the solution is non obvious. As Marty once said to me, think hard. He did not know that I think hard. He should think hard too as he reads this, and try to understand what I mean.

Personally I feel you did a great job with the information available at the time and its held up better than some.
The technology and knowledge have moved on but in a lot of cases it still holds up well and properly applied it is still usable.
Looking forward to the next version.

 

[adamasgem]

Date: 3/3/2007 3:11:54 PM
Author: strmrdr
As for the lowered standards that is the trend in education in the US all over not just GIA.

Tell me about it.. I know all too well from limited teaching at a local university. Needless to say, the adminstration was not too pleased with me when the highest grade I gave in a class was B-, to one student who tried, and the rest got C''s and D''s.

The dept head said I couldn''t give fill in the blank questions, and had to use only true/false and multiple choice questions on exams.

I had more than one student who didn''t even try to answer a true/false question.

5 out of an 11 student class couldn''t conceptually define the sine of a right triangle, after having been given a handout on the elementary trigonometry of a right triangle, and were told they had to understand sines, cosines, and tangents conceptually, to understand the basic laws of optics (Snell''s law and Freznel Reflectivity) being taught, so they could understand how types of refractometers worked.

I was in the adjunct professors office, when a collegue teaching astronomy was wasting time having to explain to a student in his class the difference between the diameter and the radius of a circle.

PS.. I wasn''t teaching at MIT