Cloud Inclusion on on SI1 Ideal Cut - Affecting Light Return?

[antidentite]

Diamond is an AGS000, SI1 that was graded such because there''s a cloud in the middle of the pavilion that''s viewable under the microscope, or upon VERY close inspection.

Will this cloud reduce the overall light return of a round brilliant diamond? Cut is the most important factor, and clarity is the least as long as it''s eye clean. But I want to make sure that a "cloudy" AGS000 doesnt cancel out the Ideal cut...

 

[oldminer]

Only those tools which directly measure the light return can tell you what your particular diamond is doing. Comparing such a result to a predicted, theoretical result, as used by other grading techniques is not yet possible because their is no standardizaion of the grading parameters. If you had not only your SI1 diamond, but an identically cut, flawless one, to also test, you could tell how much degradation the cloud made in your diamond to its light performance. There is no program I have heard of which adds in the existence of inclusions to adjust the light return in a predictive manner. Only direct measures give results which work with each specific diamond and their inclusions. No doubt, the opposing view point can contend inclusions in most stones have little effect, but you sould ask "How do you confirm this statement?" "What facts are you relying upon to make that claim?" I believe experts intuitively understand that many inclusions have a negligible impact on appearance, light, but we have no factual basis to say when an inclusion is a negative or not.

Right now, we can measure light return or predict light return, but we cannot adjust up or down in a factual way for inclusions. All we can say is either what we measure on your particular diamond or what a flawless diamond would do without any inclusions.

 

[Regular Guy]

Antidentite,

1) Extensive discussion here...though you may have seen it, or others like it...raising your question to begin with.

2) Dave offers a solution in the form of equipment that is somewhat unique to his lab, which seems too bad. Dave...don''t you have some experience with this category of diamond...such that you would offer an opinion? Regardless...except for Wink...no other expert has approached this topic with anything like an opinion...(no...maybe JQ has) since it was recently raised, either, so you''re not alone.

3) Finally, on the offer of your solution...

Date: 11/24/2007 7:20:58 AM
Author: oldminer
If you had not only your SI1 diamond, but an identically cut, flawless one, to also test, you could tell how much degradation the cloud made in your diamond to its light performance.

...do you provide this set up...of similar diamonds, that the shopper cannot buy from you, but compare their "in-hand" option to? So they can make the kind of comparison you suggest. I understand you must reference categories of numbers...but how do you let the people who come by your shop make the kind of linkages in analysis you''re suggesting?

4) I''m nothing like an expert. Maybe Dave has a helpful response to #3, though not sure where you are with respect to Philadelphia. (Dave...these responses do seem to be more political in nature than helpful). Meanwhile...seems like the only positive action you can take IS suggested by Oldminer...you''d perhaps need to take that option...that may (or may not?) have been discounted for the clouds, and compare it...really...as Dave has said, to others without the clouds. But...without this ability to compare...or...if you don''t trust your own sense of optics to generalize in sufficient situations...my own thought on this is...in a world with options...and where experts will recognize controversy...just try to avoid controversy. It''s a bit easier that way.

 

[oldminer]

No political agenda here. My fortune or lack of fortune does not hinge on ImaGem technology. I have been a consultant to this firm for 10+ years, but have only an extremely tiny interest, 4/10 of 1% of non-voting stock, if it ever takes off. EGL-USA has adopted ImaGem, and we use it for a very major US chain, but progress is slow overall. We'll see in time what transpires.

I force feed the results of ImaGem to Internet consumers and to my local community. Few folks ask for it, but it is a grading system which I believe is very valid. Every current cut grade system out there has varying degrees of validity to them. They are not all equal as some might wish you to believe. The financial size of the grading lab, large or small, does not change the validity or lack of validity. It is the inherent nature of the system being used, not the provider.

We have lots of experience with AGS 000 diamonds and I have yet to see one which was less than "beautiful". However, GRADING is not using adjectives in a subjective way. Beauty remains in the eye of the beholder. Garry H showed me a GIA 'Very Good" stone over the Summer which was "unbeautiful". If that stone is deserving of "very good" then any grades lower are a waste of time with such a system. A good system has several distinct top grades, just like diamond color and diamond clarity grading already has. Microscopic differences may exist way beyond naked eye observability. Measuring these differences is what GRADING is all about when it comes to a diamond.

I could not possibly offer to compare a diamond to any "perfectly matched" sample I might have. The point I obviosuly failed to make is that EVERY DIAMOND is unique in exact cutting and there just are no EXACT matches. In other words, it can't be done this way. You will never have physical Diamond Cut Master Sets because you cannot cut diamonds identically. At some point a "standard" will become accepted and people using the technological devices, properly calibrated, will get standardized, repeatable, universally accepted results no matter where in the world a stone is examined. Since parameters alone cannot give completely reliable results, because of 'inclusions" or because they are cut differently than a measuring device can measure, only a direct measurement tool will be potentially the proper tool for GRADING.

This is a plain and simple truth. There has never been any system of GRADING by predictive tool where direct measurement can be applied. I have asked many times for an example to the contrary and believe at this point no such response exists. Predictive grading best belongs to the creation of well cut diamonds and new cutting designs. It is a superb diamond cutting factory tool. Lab grading should be per stone based on directly measured results. The need to agree upon standards is crucial to use and acceptance of any grading tool. I do hope for that time to arrive.

 

[Lynn B]

Interesting thread.

I guess the OPs best course of action, then, would be to look at as many AGS-0 stones as possible, and then s/he would hopefully feel better "qualified" to know if the particular diamond in question has indeed had its performance compromised by its clarity grade. Which, BTW, I would personally seriously doubt, although I am totally NOT an "expert" by any means. But afterall, the diamond still earned AGS''s highest rating of "0" in light performance. I bet it''s a beauty.

 

[Regular Guy]

Date: 11/24/2007 12:28:11 PM
Author: Lynn B
Interesting thread.

But afterall, the diamond still earned AGS''s highest rating of ''0'' in light performance. I bet it''s a beauty.

Lynn,

In a sense...your point is David''s...and needs to...i think...be a criticism to AGS for over representing. AGS does inference grading, I believe...not direct "light performance" grading...which meaning it is easy to imply. IF there is any dynamic, purported as linked above by Garry, that would cause a diamond''s performance to be diminished by a cloud...I don''t think AGS''s system is designed to recognize this. The AGS system looks at how proportions interact to provide light performance. based on "light tracing" for those proportions. Once the "measures" of the diamond are taken, the diamond itself is then ignored. So...any diminution of actual performance, again...as I understand it...is not recognized by that system of grading.

Perhaps David above is answering the question. And...some overall measure...or relativism is what is needed.

Also, I misspoke, I think, earlier. Denver addressed this at least once, recently before. But...seems the discussion has not been as extensive as the concern, overall. Seems like...on these more ''racy" subjects, it is only the vendors who are wont to stick their neck out. Maybe that is for the good.

I wonder if Jonathan would care to comment? I have to think opinion on this will be related to seeing large, raw quantities of diamonds...and making a judgement from having seen the outcome of that.

 

[Garry H (Cut Nut)]

Date: 11/24/2007 2:54:56 AM
Author:antidentite
Diamond is an AGS000, SI1 that was graded such because there''s a cloud in the middle of the pavilion that''s viewable under the microscope, or upon VERY close inspection.

Will this cloud reduce the overall light return of a round brilliant diamond? Cut is the most important factor, and clarity is the least as long as it''s eye clean. But I want to make sure that a ''cloudy'' AGS000 doesnt cancel out the Ideal cut...

In my experiance if the stone had no other inclusions it is possible that it could affect the appearance / beauty and I would want someone experianced to give you a second opinion.

If it had say another inclusion that by itself was VS2, then it is unlikely to be an issue.

 

[oldminer]

I think experts acknowledge that extremely tiny differences in cutting do play some role in overall light return. These differences are well beyond what can be seen with the naked eye. The same logic leads me to believe that inclusions which are not visible to the naked eye may change the light return of a diamond. How much change is open for debate and it could be only a little quite often, maybe none on occasion and possibly more than one might expect on another. The fact that our eyes are not as good as our electronic tools for making measures is really not something unexpected. At the very base of things we use rulers and tape measures. When we measure diamonds we use digital devices because we can''t see .02mm differences that really matter. When we look for inclusions we use microscopes and when we look at color we need comparison stones or color grading digital devices. Our eyes are the best tools our bodies have, but our minds have created better instruments to measure our universe.

The concept of ray tracing does ignore inclusions. Consumers primarily don''t opt to buy flawless diamonds and want to know how their diamond performs, not how their diamond, if flawless, miight perform.

I have said many times that I have never seen a newer version of AGS 000 in a round cut which was unattractive or anything except beautiful. Parameters are excellent screening tools and our eyes remain our best judges of what is beautiful. I have never seen an AGS 000 SI1 round that was anything but beautiful. However, the SI1 may play some negative role in a measured performance scenario. Saying that clarity does not play a role in light behavior is naive. I''d suggest that light behavior might begin to be altered by the time one gets to VS1, but my eyes don''t know it. There is no way I know of currently to test this hypotheseis with any available device.

If you look at the millions of folks who have happily purchased finely cut SI1 diamonds, you must realize that this discussion must emphasize that you probably will love an AGS 000 SI1. We are arguing or presenting good points of interest and knowledge, but the truth that SI1 diamonds can be excellent choices for daily wear is not problematic at all.

 

[aljdewey]

I think this thread is an example of trying to give too much of an answer, with the result being no meaningful answer at all!

Antidentite: If your diamond is a present-day graded AGS0, it has scored a 0 for light performance. If that''s so, then the cloud isn''t affecting performance.

If it''s an old-AGS grading report (doesn''t include a light performance grade), then you can easily confirm that it''s a performer by taking it to an independent appraiser to eyeball it for you.

All that said, it''s been my understanding that it''s uncommon for inclusions in SI1 stones (even clouds) to substantially impact a diamond''s performance.

What I''m trying to tell you: there''s a difference between what''s measurable and what''s discernable. I highly doubt your cloud has any discernable effect on your stone''s performance.

 

[Regular Guy]

Date: 11/25/2007 9:26:26 AM
Author: aljdewey

Antidentite: If your diamond is a present-day graded AGS0, it has scored a 0 for light performance. If that''s so, then the cloud isn''t affecting performance.

Al, why do you write this?

Read the above again. Note Dave''s recent comments: "The concept of ray tracing does ignore inclusions."

Neither the new or old AGS strategy represents a safeguard for inclusions.

Although...yes...the marketing presentation of the words "light performance" do lead you to think you have a special protection from this.

 

[oldminer]

It is too much of an answer for the question. The world of knowledge and information is far more vast than what one person needs to know. However, different people want different amounts on knowledge on the many subjects of their personal greater interests. When I see interest in a subject that I feel competent in, I share, but it is only for those who care to know more. Many folks simply will say the offering is over the top, but it is not for them to judge for others who have a greater desire to know more about a particular issue.

The world of diamond grading has traditionally relied upon loupes, microscopes, and color master sets for the GIA system of diamond grading. We gave up pure reliance on the naked eyes for diamond grading many decades ago. Now we are entering an age of increased technology where we can further fine tune our grading of things such as diamond cut with tools follow the model of using tools to better grade clarity and color.

Beauty is a simple thing for individuals to judge for themselves. No doubt, a trained eye is better at this judgment, but each one of us is entitled to judge on our own with whatever innate sense we have about it. "Beauty is in the eye of the beholder" is a worthy phrase which we respect, but it is inherent in our curious nature to want to quantify and understand what we perceive. Right or not, we work all the time to break down the elements of beauty into smaller bits so that we can at some future time "grade" it. I know this is a jarring thought or possibly a needless quest, but it seems to be what humankind likes to do. Right now we can do a pretty good job of defining components which create beauty, but there is enough left to the unknown yet that we still find work which can be done. This is just one of those things which interests me and those I associate with. I see this as a natural human pursuit of knowledge and never wish to see the visual appreciation of beauty turned into a mathmatical formula. I''m sure this won''t ever happen.

 

[strmrdr]

There is no way anyone here can say yes or no or how much the inclusion is affecting the stones performance.
A in person expert evaluation by someone skilled in ideal cut diamonds is the only way.

My opinion is that if there is an effect its a very small one and the lower cost of si graded stones offset any tiny performance difference in almost all cases. (some si2 and clouds being the most common exception)
An expert vendor or appraiser can sort out the exceptions and that is one of the things we pay them for!

 

[Regular Guy]

Date: 11/25/2007 10:35:37 AM
Author: strmrdr
There is no way anyone here can say yes or no or how much the inclusion is affecting the stones performance.
A in person expert evaluation by someone skilled in ideal cut diamonds is the only way.

My opinion is that if there is an effect its a very small one and the lower cost of si graded stones offset any tiny performance difference in almost all cases. (some si2 and clouds being the most common exception)
An expert vendor or appraiser can sort out the exceptions and that is one of the things we pay them for!

I hope an expert eye-balling the diamond will give the desired result. But...I am again mindful of what Dave notes above:

"The world of diamond grading has traditionally relied upon loupes, microscopes, and color master sets for the GIA system of diamond grading. We gave up pure reliance on the naked eyes for diamond grading many decades ago. Now we are entering an age of increased technology where we can further fine tune our grading of things such as diamond cut with tools follow the model of using tools to better grade clarity and color."

Experts won''t say...that''s a G..or an I. They''ll refer to a master set to compare. So...what''s an expert to do with a well graded diamond...with a cloud. What''s the reference...to make a determination about diminution of light performance?

At least Dave gives it some kind of shot with Imagem.

To my point of view...if you are willing to step into controversy (rather than taking a pass)...you need to feel you''ve compared to alternatives without the blemish. Or...you don''t. But...of course, you can get the alternative without the blemish...so why not make an educated choice. Certainly...if it''s simply a matter of the SI option showing up conveniently, but it happens to have a cloud...and does it really matter anyway. Just say yes. Alternately, if you''re getting a discount (and, as Storm suggests...such discounts in the form of retained cash) are always of value...see what it''s worth.

But my long winded question here is...how can an appraiser really tell? Imagem is perhaps, genuinely, one answer (though an answer whose meaning may be challenging to contextuallze). What other answers are there?

 

[JohnQuixote]

Date: 11/25/2007 10:35:37 AM
Author: strmrdr
There is no way anyone here can say yes or no or how much the inclusion is affecting the stones performance.
A in person expert evaluation by someone skilled in ideal cut diamonds is the only way.

My opinion is that if there is an effect its a very small one and the lower cost of si graded stones offset any tiny performance difference in almost all cases. (some si2 and clouds being the most common exception)
An expert vendor or appraiser can sort out the exceptions and that is one of the things we pay them for!

100% right.A good gemologist can answer this but he/she must have the diamond in-hand.

We all counsel caution, especially in the sight-unseen market, but we should not blow this out of proportion. Grade setting clouds in SI stones do not always hinder performance. Remember that clouds are just clusters of pinpoints.Some are denser than others.If the cloud is large but spread out it may be setting the grade but is not any kind of optical issue…If the pinpoints are especially dense an experienced grader knows what to look for. Gemologists go much farther than 10X in a thorough analysis (as do graders in the lab when plotting). Simple use of darkfield and diffused lighting + water/detergent on the diamond reveals an awful lot. One basic test is to turn the diamond and check for a telltale ‘shimmer,’ which is a sign that optical performance is impacted. In any event it is a stone by stone call, to be made by an expert in-person.

Lynn & Alj, this would not show up in the AGS light performance assessment - which places a diamond within a grade based on a 3D scan - but a clarity grader should certainly detect it.If strictly graded I feel it should really fall in the I range.

Stones with optic-hindering clouds are nicknamed ‘sleepy’ stones.They aren’t common in GIA/AGS graded diamonds but we carefully screen our inventory to reject them anyway, as do other vendors who bring in and inspect the diamonds they sell.

Date: 11/25/2007 10:52:59 AM
Author: Regular Guy

...Experts won't say...that's a G..or an I. They'll refer to a master set to compare. So...what's an expert to do with a well graded diamond...with a cloud. What's the reference...to make a determination about diminution of light performance?...

Ira, gemologists have been performing these tests for decades. We see thousands of SI stones per year in the shop and I trust our gemologists to screen anything of significance - just as I trust other top appraisers and gemologists I know. Every pro I feel is worthy of trust looks for sleepy stones as well as overblues, durability concerns and a dozen other issues that aren't covered on the grading report.

No doubt science & technology will continue to improve far beyond human perception - eventually Sarin/Helium will have no error. Mechanical color/clarity grading will mature to the point that we can identify D 150/400 vs D 151/400 and cloud density 0.0037 vs 0.0086, etc. Those things will be far beyond human perception.

For now maybe you can focus this concerned energy on business models where diamonds are drop-shipped to the customer without the seller or a credentialed gemologist ever having seen them... Those consumers are not being protected against any of this.

 

[Regular Guy]

JQ,

You make a case.

For now however...

Date: 11/24/2007 3:50:04 PM
Author: Regular Guy
But...seems the discussion has not been as extensive as the concern, overall. Seems like...on these more 'racy' subjects, it is only the vendors who are wont to stick their neck out. Maybe that is for the good.

I might prefer to stand by my earlier comments. You won't find what you're not looking for...i.e. understand materially would not pertain.

 

[strmrdr]

Date: 11/25/2007 1:19:15 PM
Author: Regular Guy
JQ,

You make a case.

For now however...

Date: 11/24/2007 3:50:04 PM
Author: Regular Guy
But...seems the discussion has not been as extensive as the concern, overall. Seems like...on these more 'racy' subjects, it is only the vendors who are wont to stick their neck out. Maybe that is for the good.

I might prefer to stand by my earlier comments. You won't find what you're not looking for...i.e. understand materially would not pertain.

RG.. how is this ,,, a while back I was comparing 2 stones side by side, a G/I1 that had nice eye visible arrows and while I didnt have my IS with me looked very very well cut and an eye visible at 10 inches inclusion(large crystal), GIA graded old report without cut grade,
The other stone was a D/IF GIA graded old report. Both 1ct even.
Care to guess which was the more beautiful diamond?
.
.
.
.
.
.
The D/IF was a total dog and the G/I1 was very sparky enough so that I would consider it for a pendant where someone wouldn't generally look at it too close and because of the price.
Was the inclusion interfering with total light performance, yep it was! but the stone still rocked because the cut was right.

 

[JohnQuixote]

Date: 11/25/2007 1:19:15 PM
Author: Regular Guy

Date: 11/24/2007 3:50:04 PM
Author: Regular Guy
But...seems the discussion has not been as extensive as the concern, overall. Seems like...on these more ''racy'' subjects, it is only the vendors who are wont to stick their neck out. Maybe that is for the good.

I might prefer to stand by my earlier comments. You won''t find what you''re not looking for...i.e. understand materially would not pertain.

Touche'' Ira. You are a great remember-er of things. I imagine Garry (who is well-traveled) was stung by something he saw. I would say that this, and other cases where premium lab paper is not representative of the diamond, are rare exceptions rather than rules. To say the sky is falling (get it? clouds? haha) is alarmist, but I think your good memory in bringing this forward lends itself to the prior point:

Diamonds are all different. None are identical, no matter how similar on paper. When spending thousands of dollars a consumer should expect to be protected from any ''exceptions'' to the rules; whether by the seller earning his/her business or another trusted expert in the loop.

 

[Garry H (Cut Nut)]

Date: 11/25/2007 10:35:37 AM
Author: strmrdr
There is no way anyone here can say yes or no or how much the inclusion is affecting the stones performance.
A in person expert evaluation by someone skilled in ideal cut diamonds is the only way.

My opinion is that if there is an effect its a very small one and the lower cost of si graded stones offset any tiny performance difference in almost all cases. (some si2 and clouds being the most common exception)
An expert vendor or appraiser can sort out the exceptions and that is one of the things we pay them for!

100% agreement Storm

 

[aljdewey]

Date: 11/25/2007 9:49:03 AM
Author: Regular Guy

Date: 11/25/2007 9:26:26 AM
Author: aljdewey

Antidentite: If your diamond is a present-day graded AGS0, it has scored a 0 for light performance. If that's so, then the cloud isn't affecting performance.

Al, why do you write this?

Read the above again. Note Dave's recent comments: 'The concept of ray tracing does ignore inclusions.'

Ira.....I write it because I believe it to be true.

Perhaps instead of clipping a portion of what I wrote, you should have read the whole thing. DISCERNABLE vs. MEASURABLE, Ira.

I don't have a reading comprehension problem, so there's no need for me to reread Dave's comment. And Ira, I'm not talking about ray tracing.

YOU keep focusing on the 'measureable' part.....and I'm focusing on the "does it really matter/make a difference" part.

Lemme 'splain this way. If I were sitting in front of two five-gallon water jugs, and I put a single drop of Diet Pepsi into one of the two containers, I'm quite certain there's some gadget out there that could analyze the composition of the liquid in each container and definitively tell me which one has the drop of soda in it. That's what devices are calibrated to do. However, I'm equally certain that no one would be able to tell by taste which container was altered.

To me, the second part of the equation (what can be discerned) is FAR more important than the second (what can be measured).

What do you SERIOUSLY think the OP's primary concern is? He wants to know if the cloud will negate his great cut. He didn't ask if it's measureable to the ten-thousandth of a degree, for god's sake! For once, it would be nice if the techie types could step back from analyzing the composition of the tree and just appreciate the forest.

 

[johngalt2004]

So when ags grades for light performance, do they actually put the stone in an ASET scope and make a determination? By an expert observer? Or do they do a ray trace and make assumptions based on proportions? I have read too much and am muddled on this topic.


Is there a live personal analysis of light performance in the ags grading? person looking at the stone? Or is it all assumptions based on a scanned model?


Was an ags zero looked at by a person and evaluated based on light performance or not?

 

[Regular Guy]

Date: 11/25/2007 3:32:58 PM
Author: aljdewey

What do you SERIOUSLY think the OP's primary concern is? He wants to know if the cloud will negate his great cut. He didn't ask if it's measureable to the ten-thousandth of a degree, for god's sake! For once, it would be nice if the techie types could step back from analyzing the composition of the tree and just appreciate the forest.

(edited to add)...JohnGalt...I'll leave to an expert to answer you...but this discussion should be of interest...

Al, I think it was both the tree and the forest that motivated this early recent thread on the topic. I hadn't been tracking the source of the diamond from Antidente; maybe you had.

Much of what I do read lately suggests that...at least without noting the source (and more conservatively, even after knowing it)...knowing alone that it is a) graded by AGS or GIA, b) regardless of the type of cert, c) that it is either SI 1 or 2..., and d) if it has clouds or graining as the grade maker...then this is not sufficient to know about the performance of the diamond...independent of its cut, for what would be recommended as a sound purchase decision.

This is not consistent with your stated comfort points (as above, where you say: "If your diamond is a present-day graded AGS0, it has scored a 0 for light performance. If that's so, then the cloud isn't affecting performance.")...(though it is possible AGS is that much more strick than GIA, etc.)

And as they used to say in Seinfeld...not there's anything wrong with that...

 

[Lynn B]

Alj,

Great post -- and excellent analogy! Thanks!

Lynn

 

[Garry H (Cut Nut)]

Date: 11/25/2007 4:01:05 PM
Author: johngalt2004
So when ags grades for light performance, do they actually put the stone in an ASET scope and make a determination? By an expert observer? Or do they do a ray trace and make assumptions based on proportions? I have read too much and am muddled on this topic.

no - they make a 3D scan of the outside only of the diamond, and then use a mono ray tracing system to count the pixels for ASET and other factors
Is there a live personal analysis of light performance in the ags grading? person looking at the stone? Or is it all assumptions based on a scanned model?

I do not believe AGS grade light performance by looking at the diamond. In theory a black diamond could get a high grade (but the color would give the game away )

Was an ags zero looked at by a person and evaluated based on light performance or not?

 

[Garry H (Cut Nut)]

Date: 11/25/2007 3:32:58 PM
Author: aljdewey

Date: 11/25/2007 9:49:03 AM
Author: Regular Guy

Date: 11/25/2007 9:26:26 AM
Author: aljdewey

Antidentite: If your diamond is a present-day graded AGS0, it has scored a 0 for light performance. If that''s so, then the cloud isn''t affecting performance.

Al, why do you write this?

Read the above again. Note Dave''s recent comments: ''The concept of ray tracing does ignore inclusions.''

Ira.....I write it because I believe it to be true.

Perhaps instead of clipping a portion of what I wrote, you should have read the whole thing. DISCERNABLE vs. MEASURABLE, Ira.

I don''t have a reading comprehension problem, so there''s no need for me to reread Dave''s comment. And Ira, I''m not talking about ray tracing.

YOU keep focusing on the ''measureable'' part.....and I''m focusing on the ''does it really matter/make a difference'' part.

Lemme ''splain this way. If I were sitting in front of two five-gallon water jugs, and I put a single drop of Diet Pepsi into one of the two containers, I''m quite certain there''s some gadget out there that could analyze the composition of the liquid in each container and definitively tell me which one has the drop of soda in it. That''s what devices are calibrated to do. However, I''m equally certain that no one would be able to tell by taste which container was altered.

To me, the second part of the equation (what can be discerned) is FAR more important than the second (what can be measured).

What do you SERIOUSLY think the OP''s primary concern is? He wants to know if the cloud will negate his great cut. He didn''t ask if it''s measureable to the ten-thousandth of a degree, for god''s sake! For once, it would be nice if the techie types could step back from analyzing the composition of the tree and just appreciate the forest.

Aljd, is Storm and my rare agreement alos in agreement with you?

We both suggest experianced eyes make the final call.

 

[aljdewey]

Ira.....no, I had not been tracking the source of his stone.

Ira, PLEASE......go back and read the initial question. The issue (paraphrased) is "will the cloud diminish light performance to a significant enough degree that it will nullify the benefit of buying an ideal cut stone".

You guys can sit here and split hairs all day long about the hundredth/thousandth degree it *might* be affected compared to a flawless stone (which isn''t the point, by the way). Maybe you guys just love arguing about the smallest, most remote possibilities, and that''s great. But you''re MISSING THE POINT.

Even if it would be MINIMALLY affected, minimally doesn''t mean discernable. It doesn''t mean ''enough to nullify the purpose of buying an ideally cut stone." Seriously, Ira, just how many ''sleepy'' stones do you think are getting by the EXPERTS at the grading labs?

Forest......trees.

Garry: I''ve ALWAYS suggested experienced eyes make the final call.....that''s nothing new.

I guess the point I''m trying to get at: There is a WIDE gulf between possible and probable, and at times, the propensity here to focus on the most low-probability things and make mountains out of proverbial molehills DOES NOT really help or best serve the person asking.