GIA grades - a few recent observations

[Garry H (Cut Nut)]

I had an Israeli dealer visit recently and looked at quite a few GIA stones.

Here are a few random observations:

1. SI clarity grades - when there is no easy to loupe inclusions should be avoided when buying on-line as I saw cloudy clearly duller stones. It worries me when people spend a lot of time trying to avoid this and that type and size of inclusion. I prefer an honest middle of the road sized SI inclusion to the so called bargain stone that the labs miss graded. They can miss inclusions, but they do not downgrade stones for no reason at all - ever! So do not try to out expert them.

2. I have seen GIA good diamonds (downgraded for proportions) that knock the sox off GIA steep deep Excellents.

3. Some Good symmetry downgrades still show H&A''s and are bargains

4. Another supplier sent me a GIA G that is clearly not a G - it is a mid H (and we will sell it for H because it will cost too much to return it)

No real purpose for this post, but others might have recent experiance with GIA or other labs and like to share?

For example DiaGem''s recent experiance with a potentially IF stone with a big natural that was given VS1 by GIA https://www.pricescope.com/community/threads/effect-of-a-natural-on-a-clarity-grade.65969/ - it is intersting to understand the rules - it reminds me of the womens rules joke - when any man discovers a rule - the woman must change it.

 

[WorkingHardforSmallRewards]

hey, I asked you about this in an earlier thread but I don't think you saw it. I was just curious because you have recently been making a couple of comments wherein you have displayed some real concern for SI1 (and below) clouds causing the diamond to look "sleepy." I have a couple of questions on this.

First, is there really a significant difference between SI1 and VS2 such that you would be concerned about clouds in SI1 causing the diamond to be sleepy, but that you would think it is very unlikely (and thus wouldn't be concerned) for them to cause the diamond to be sleepy in a VS2? Or are they close enough that you would have some real concerns for both SI1 and VS2, but just not quite as much concern for the VS2?


also, do you have any general guidlines, as I have read online a few times, about clouds that cover X% of the diamonds diameter and it thus causing for performance effects, etc? any other rules so that a consumer learning more about the types of inclusions or clouds present in a case by case basis could use to get a general idea on the probability of whether the diamond will be sleepy or not?

and finally, and really the question I am most interested in:

Would the IS image of the diamonds you are mentioning or others like them have a noticeable change in order to account for that hazy, dull or "sleepy" appearance? and if so exactly how would that change be noted?



and since you just mentioned it

one more what kind of symmetry downgrades would be present that would still allow for the hearts and arrows to be displayed in a Good symmetrical rating?

 

[Garry H (Cut Nut)]

Date: 8/3/2007 9:33:36 PM
Author: WorkingHardforSmallRewards


First, is there really a significant difference between SI1 and VS2 such that you would be concerned about clouds in SI1 causing the diamond to be sleepy, but that you would think it is very unlikely (and thus wouldn''t be concerned) for them to cause the diamond to be sleepy in a VS2? Or are they close enough that you would have some real concerns for both SI1 and VS2, but just not quite as much concern for the VS2?

I doubt a VS2 can be sleepy.
I saw a stone graded SI2 that thru the loupe would be called VS2 based on its apparent grade makers - but the clouds in my book should have resulted in more than a 20% drop in price - I would have had to have sold it as I1 to sleep soundly.

You can find GIA VS stones that have hazy whitish graining visible maybe even to the naked eye from one narrow direction only. I think that is fair.

Date: 8/3/2007 9:33:36 PM
Author: WorkingHardforSmallRewards

also, do you have any general guidlines, as I have read online a few times, about clouds that cover X% of the diamonds diameter and it thus causing for performance effects, etc? any other rules so that a consumer learning more about the types of inclusions or clouds present in a case by case basis could use to get a general idea on the probability of whether the diamond will be sleepy or not?

A perfect example of a consumer trying to be too clever WH4SR.

If the cloud is high in the stone near the table or crown facets it could be very big and have less effect than 1/4 of the same cloud bnear the culet.

Date: 8/3/2007 9:33:36 PM
Author: WorkingHardforSmallRewards
and finally, and really the question I am most interested in:

Would the IS image of the diamonds you are mentioning or others like them have a noticeable change in order to account for that hazy, dull or ''sleepy'' appearance? and if so exactly how would that change be noted?

Often it can be seen thru IS by an epxperianced person - in a photo one click of "sharpen image" would remove the visual.

Date: 8/3/2007 9:33:36 PM
Author: WorkingHardforSmallRewards

and since you just mentioned it

one more what kind of symmetry downgrades would be present that would still allow for the hearts and arrows to be displayed in a Good symmetrical rating?

read this page http://www.gemology.ru/cut/english/symmetry/6.htm the example was a GIA Good sym stone

 

[elmo]

Garry, did the H that graded as a G involve any of the usual suspects for more tricky color grading e.g. a non-"cape" tint like brown in a large fancy shape stone? Or was it just a blown call on a 1 carat round?

 

[Garry H (Cut Nut)]

Date: 8/4/2007 1:35:29 PM
Author: elmo
Garry, did the H that graded as a G involve any of the usual suspects for more tricky color grading e.g. a non-''cape'' tint like brown in a large fancy shape stone? Or was it just a blown call on a 1 carat round?

1ct ordinary old round with non (actually feint) fluoro and cape series (yellowish). of course it faces up like DE because it is a great make.

 

[strmrdr]

Hey Garry your as clear as mud on what your trying too say.

A si stone with a cloud as the grade maker needs to be evaluated by a trusted vendor or appraiser when buying online is what your talking about right?
If thats not possible then a grade setting si feather or crystal is a better choice?

 

[Garry H (Cut Nut)]

Date: 8/4/2007 11:57:13 PM
Author: strmrdr
Hey Garry your as clear as mud on what your trying too say.

A si stone with a cloud as the grade maker needs to be evaluated by a trusted vendor or appraiser when buying online is what your talking about right?
If thats not possible then a grade setting si feather or crystal is a better choice?

No.
For SI stones:

If the cloud is the grade setter then pass.
If the plot has little or nothing on it - pass

If the photo has little or nothing in then pass

And the aim of having no table inclusions then the crown ones will be easier to see and be bigger


Consumers and prosumers trying to outsmart labs is, welll, really quite stoopid

 

[strmrdr]

Date: 8/5/2007 3:26:34 AM
Author: Garry H (Cut Nut)

Date: 8/4/2007 11:57:13 PM
Author: strmrdr
Hey Garry your as clear as mud on what your trying too say.

A si stone with a cloud as the grade maker needs to be evaluated by a trusted vendor or appraiser when buying online is what your talking about right?
If thats not possible then a grade setting si feather or crystal is a better choice?

No.
For SI stones:

If the cloud is the grade setter then pass.
If the plot has little or nothing on it - pass

If the photo has little or nothing in then pass

And the aim of having no table inclusions then the crown ones will be easier to see and be bigger


Consumers and prosumers trying to outsmart labs is, welll, really quite stoopid

Have too say I disagree, I trust Brian, Jon, Paul, Wink, Gary and a few others too weed out the problem stones for me.
There are no absolutes.
If buying from a drop shipper then I would agree more with you.

 

[Garry H (Cut Nut)]

Date: 8/5/2007 3:42:30 AM
Author: strmrdr

Date: 8/5/2007 3:26:34 AM
Author: Garry H (Cut Nut)

Date: 8/4/2007 11:57:13 PM
Author: strmrdr
Hey Garry your as clear as mud on what your trying too say.

A si stone with a cloud as the grade maker needs to be evaluated by a trusted vendor or appraiser when buying online is what your talking about right?
If thats not possible then a grade setting si feather or crystal is a better choice?

No.
For SI stones:

If the cloud is the grade setter then pass.
If the plot has little or nothing on it - pass

If the photo has little or nothing in then pass

And the aim of having no table inclusions then the crown ones will be easier to see and be bigger


Consumers and prosumers trying to outsmart labs is, welll, really quite stoopid

Have too say I disagree, I trust Brian, Jon, Paul, Wink, Gary and a few others too weed out the problem stones for me.
There are no absolutes.
If buying from a drop shipper then I would agree more with you.

We have no need to disagree when we are talking about real human advice from real people with real reputations and or real relationships Storm.

You have challenged me many times about foxes and hen houses when I have mentioned that I trust certain trade vendors opinions way higher than any lab. A vendor knows what you like because after you have looked at their goods and haggled over the 10 or 100 stones you could buy, we end up being very honest with each other.

 

[WorkingHardforSmallRewards]

and on that same note, I have seen a fair number of people looking at diamonds where no inclusions are visible in SI1''s and even SI2''s at 10-40X magnification. I think those diamonds where the inclusions are not visible or are barely visible at 40Xmag would probably qualify for this warning and honestly I have seen a number of them being discussed here on PS...

 

[strmrdr]

Date: 8/5/2007 6:23:44 AM
Author: Garry H (Cut Nut)

We have no need to disagree when we are talking about real human advice from real people with real reputations and or real relationships Storm.

You have challenged me many times about foxes and hen houses when I have mentioned that I trust certain trade vendors opinions way higher than any lab. A vendor knows what you like because after you have looked at their goods and haggled over the 10 or 100 stones you could buy, we end up being very honest with each other.

Its kewl Garry I just don''t want anyone getting the wrong idea and someone will.
I can see it now "help this ( insert name of stocking PS vendor) sold me a diamond with a si1 that has a cloud and nothing on the plot and Garry says that is bad.

Self grading and a vendor sorting si stones for problems and "eyeclean" are 2 different things.

 

[strmrdr]

Date: 8/5/2007 6:47:27 AM
Author: WorkingHardforSmallRewards
and on that same note, I have seen a fair number of people looking at diamonds where no inclusions are visible in SI1's and even SI2's at 10-40X magnification. I think those diamonds where the inclusions are not visible or are barely visible at 40Xmag would probably qualify for this warning and honestly I have seen a number of them being discussed here on PS...

See Garry the post that I didn't read before replying above that proves my point.

WHSR: if such a stone has been looked over by a skilled and trusted vendor then there is no issue with them.
Some vendors are good enough at taking pictures that they could hide almost any inclusion while others use darkfield that shows most any grade setting inclusion some even point then out with arrows.

 

[WorkingHardforSmallRewards]

but honestly, it makes sense you could find a stone that has been misgraded as higher than it should be. but graded lower than it should be doesn''t really make any sense at all does it? Surely a stone is considered, before being looked at, to be an IF right? they don''t look at them and say "this is an I3, lets find out how much of the diamond is clean". instead they look for where the inclusions are. So if they don''t find any, it won''t get marked down, and when they do, they determine what that inclusion is. It makes more sense to think that, more frequently than seeing something that wasn''t there or considering something worse than it was, they would overlook something.

So to have a plethora of diamonds out there graded as SI1--meaning that at 10X magnification it is somewhat difficult to locate, and then putting that same diamond at 40Xmag and it is impossible to find anything. Well...what on earth were they thinking when the graded it at 10X mag as an SI1? just making up inclusions? of course not, they had a reason, and if you can''t see it...well then, that goes back to Gary''s point. It is there, and if you can''t see it at 40X mag or there were so many that were so small that they didn''t merit a pen stroke on the inclusion chart, but they still felt it was damaging enough to merit an SI1, then it is probably having a significant impact on performance. It seems pretty logical to me, and I can''t really see any logic in there being SO MANY of those "excellent" SI1''s as I have seen mentioned on PS regardless of who the vendor is. It makes me wonder is all, though I was wondering about it before Gary''s post I just didn''t have any basis to begin vocalizing.

 

[strmrdr]

Date: 8/5/2007 11:41:03 AM
Author: WorkingHardforSmallRewards
So to have a plethora of diamonds out there graded as SI1--meaning that at 10X magnification it is somewhat difficult to locate, and then putting that same diamond at 40Xmag and it is impossible to find anything. Well...what on earth were they thinking when the graded it at 10X mag as an SI1? just making up inclusions? of course not, they had a reason, and if you can't see it..

lighting lighting lighting lighting and DOF and Focus point
If you saw the diamond with a diamond grading microscope at 10x and 40x and then compared it too the 40x pictures a light bulb would come on in your head.

 

[WorkingHardforSmallRewards]

Date: 8/5/2007 11:51:23 AM
Author: strmrdr

Date: 8/5/2007 11:41:03 AM

Author: WorkingHardforSmallRewards

So to have a plethora of diamonds out there graded as SI1--meaning that at 10X magnification it is somewhat difficult to locate, and then putting that same diamond at 40Xmag and it is impossible to find anything. Well...what on earth were they thinking when the graded it at 10X mag as an SI1? just making up inclusions? of course not, they had a reason, and if you can''t see it..

lighting lighting lighting lighting

If you saw the diamond with a diamond grading microscope at 10x and 40x and then compared it too the 40x pictures a light bulb would come on in your head.

So why, then, would such reputable men and businesses advertise their lower clarity grade diamonds at 40X mag, when in fact it makes the inclusions more difficult to see due to lighting (other, of course, than for that very reason, which in turn creates the sarcastic element in my first line).

Don''t get me wrong, I have tremendous respect for PS vendors, but even they should still be handled critically and should have their actions evaluated logically.

 

[strmrdr]

Date: 8/5/2007 11:56:00 AM
Author: WorkingHardforSmallRewards


So why, then, would such reputable men and businesses advertise their lower clarity grade diamonds at 40X mag, when in fact it makes the inclusions more difficult to see due to lighting (other, of course, than for that very reason, which in turn creates the sarcastic element in my first line).

Don't get me wrong, I have tremendous respect for PS vendors, but even they should still be handled critically and should have their actions evaluated logically.

My thoughts are darkfield pictures scare people by emphasizing the inclusions and make the stone look dark and kind ugly but is closer to inclusion grading lighting(traditionally a loupe but most labs are using scopes these days).
This is getting real close to being one PS vendor way vs another's way of doing things so I'm going to go get some sleep :}

 

[WorkingHardforSmallRewards]

fair enough to go to sleep. First I want to say that I am not mentioning any specific vendor here. I have seen the images but I honestly don't know who it was. I also don't know for sure that the said vendors have considered how lighting may masks inclusions? Nonthless, trying to be polite aside, to say that a magnified image that is being set up to (intentionally or otherwise) mask the inclusions and make the diamond look prettier, while still advertising that the purpose of the magnified images is to show how the diamond actually looks under magnification; specifically to show how the inclusions look, is a bit more than to say that it is a matter of preference between vendors. To do so is simply misleading and basically, in my eyes, no better than lying. At the very best it is being very tricky and not being open, honest, and forthright.


So, now that I am done making people angry, where are you at in the world that it is nap/night time at the moment?

 

[JohnQuixote]

Date: 8/5/2007 7:44:54 AM
Author: strmrdr

Date: 8/5/2007 6:23:44 AM
Author: Garry H (Cut Nut)

We have no need to disagree when we are talking about real human advice from real people with real reputations and or real relationships Storm.

You have challenged me many times about foxes and hen houses when I have mentioned that I trust certain trade vendors opinions way higher than any lab. A vendor knows what you like because after you have looked at their goods and haggled over the 10 or 100 stones you could buy, we end up being very honest with each other.

Its kewl Garry I just don''t want anyone getting the wrong idea and someone will.
I can see it now ''help this ( insert name of stocking PS vendor) sold me a diamond with a si1 that has a cloud and nothing on the plot and Garry says that is bad.

Self grading and a vendor sorting si stones for problems and ''eyeclean'' are 2 different things.

All good points. When searching online for a size/color that''s plentiful a consumer may have many to choose from and, if he prefers, can just ignore such stones. However if it''s a rarer size/color (or other criteria) and that person is working on a budget it''s not in his/her best interest to discard stones based on limited info. In this case it''s best to involve a trusted pro.

Grade setting clouds in an SI2 may not hinder performance but it is wise to counsel caution: If the pinpoints are especially dense the gemologist can see this. In most cases he can turn the diamond and it will show a telltale ''shimmer.'' This would be a stone to avoid. Alternately, if the cloud/s are light but very spread out through the diamond they may set the SI grade, but it might not be any kind of light performance issue. Such a diamond really must be seen by someone with expertise for a decisive judgment.

Clients are cost-sensitive and we want to help those who wish the best bang for their buck. We''re most comfortable with our own inventory and we, nor any PS seller I know, don''t stock ''sleepy'' stones - it would be the kiss of death in this market. When bringing in an SI it''s simple to make the call once we actually see it. If there''s an issue we recommend against it - and the search continues.