Just a note - this doesn't mean that all SI2s have inclusions visible to the naked eye. All SI1s have inclusions visible in the standard loupe, that's how they're graded, and some SI1s have inclusions visible to the naked eye - as do some VS2s, esp. in larger sizes
Date: 6/22/2010 1:49:03 PM
Author: John Pollard
Date: 6/21/2010 6:34:31 PM
Author: Isabelle
John, as always your knowledge is overwhelming. So interesting to note that they''re hard to even find these days and that the discount isn''t usually that much. But then why did that other PSer say she was able to get a much larger stone by going with strong fluor? In any case, when I''m back on my computer I''ll read the article you linked to. I''m currently posting from iPhone which is hard.
You''re welcome for the info. I wanted to mention that I also enjoyed reading Wink''s historical perspective.
AGS doesn''t downgrade for fluorescence. No lab does, that I know of.
It may be helpful to offer this perspective: Fluorescence discounting becomes somewhat negligible when you compare it to discounting in categories considered more significant, like color or clarity. Move from D to E in color, or IF to VVS in clarity and you''ll find a meaningful discount. Now try moving 5 grades. And, like fluorescence, the discounts may or may not reflect something that''s visible to the casual viewer.
On the overall topic GIA''s study concludes well, and offers a gentle spanking to trade members who would carrry on old wives'' tales about the ''evils'' of fluorescence:
''Unlike the notion held by many in the trade, fluorescent diamonds are not as prevalent as nonfluorescent stones, as the GIA Gem Trade Laboratory sample data for more than 26,000 diamonds showed. The present study also challenges the trade perception that fluorescence usually has a negative effect on better-color diamonds. Our results show that the diamond industry would be better served by considering each individual diamond on its own visual merits.''
Having given this perspective, it''s also important to say that it is anyone''s right to HATE fluorescence. No problem. I defend their right to hate it. To spit when they hear it. To curl their fists aloft and with angry howls break the clouds!
In such matters involving personal preference we should just remember that - as we exercise our own right to choose - it''s a good idea to respect that others may choose differently... whether fluoro, color, clarity, cut or pie flavor. It''s a two-way street.
Date: 6/22/2010 2:38:03 PM
Author: Rockdiamond
Date: 6/22/2010 1:49:03 PM
Author: John Pollard
Date: 6/21/2010 6:34:31 PM
Author: Isabelle
John, as always your knowledge is overwhelming. So interesting to note that they''re hard to even find these days and that the discount isn''t usually that much. But then why did that other PSer say she was able to get a much larger stone by going with strong fluor? In any case, when I''m back on my computer I''ll read the article you linked to. I''m currently posting from iPhone which is hard.
You''re welcome for the info. I wanted to mention that I also enjoyed reading Wink''s historical perspective.
AGS doesn''t downgrade for fluorescence. No lab does, that I know of.
It may be helpful to offer this perspective: Fluorescence discounting becomes somewhat negligible when you compare it to discounting in categories considered more significant, like color or clarity. Move from D to E in color, or IF to VVS in clarity and you''ll find a meaningful discount. Now try moving 5 grades. And, like fluorescence, the discounts may or may not reflect something that''s visible to the casual viewer.
On the overall topic GIA''s study concludes well, and offers a gentle spanking to trade members who would carrry on old wives'' tales about the ''evils'' of fluorescence:
''Unlike the notion held by many in the trade, fluorescent diamonds are not as prevalent as nonfluorescent stones, as the GIA Gem Trade Laboratory sample data for more than 26,000 diamonds showed. The present study also challenges the trade perception that fluorescence usually has a negative effect on better-color diamonds. Our results show that the diamond industry would be better served by considering each individual diamond on its own visual merits.''
Having given this perspective, it''s also important to say that it is anyone''s right to HATE fluorescence. No problem. I defend their right to hate it. To spit when they hear it. To curl their fists aloft and with angry howls break the clouds!
In such matters involving personal preference we should just remember that - as we exercise our own right to choose - it''s a good idea to respect that others may choose differently... whether fluoro, color, clarity, cut or pie flavor. It''s a two-way street.
I agree with a lot of what you wrote John- I''m a big advocate for the ''live and don''t insult other''s taste about diamonds '' part.
We might have a different perspective on the pricing issue- because we''re buying polished from a many sources- meaning that strong blue stones, which are already on the market are what I based my statement on.
Since you are representing a cutter, the discounts you offer for a strong blue might be much smaller ( justifiably so) as compared to stones on the general market.
I do disagree, slightly, about the part in bold- in one specific area. That being Fancy Light, Fancy Yellow, and Fancy Intense Yellow stones with strong blue.
It would be possible to make a case that GIA is tougher on these colors when they are strong blue- although part of this has to do with the stronger effect on perceived color these stones experience. The result is that a Fancy Yellow with Strong blue, viewed in ''normal'' lighting, may have a color as strong as an inert Fancy Intense Yellow.
Stone, the history of ACAs not allowing fluorescence has more to do with 'purist' roots (which I know John has alluded to previously) than with performance. Most would agree that fluorescence in the faint to medium range doesn't impact performance, and yet it wasn't allowed in the ACA brand at all.
Date: 6/22/2010 3:53:03 PM
Author: Allison D.
Date: 6/22/2010 1:00:26 PM
Author: dreamer_d
Date: 6/22/2010 8:01:53 AM
Author: Isabelle
That''s sort of sophistry though, isn''t it Dreamer? McDonalds isn''t known as the world''s finest purveyor of burgers. A better analogy would be for you to say that you don''t consider Ferrari to be a source of pure unbiased information about how to make a fast sports car. They might not be unbiased about their own cars, but I think most people would defer to their expertise on on how to make one run fast.
I think McDonald''s has perfected the art of marketing its goods to its target population and highlighting or spinning information in a way that meets its needs, and therin lies my comparison with a multinational corporation like Tiffany. You may not see the parallel, but I certainly do. And I would also take with a grain of salt the information that Ferrari provided in marketing information for its consumers, especially when some of that information was contradicted by many other experts.
Hee hee - lest anyone think I was talking about the ''mcdonald''s equivalent'' of a PS expert earlier....in my case, it wasn''t Tiffany.
The topic of the GIA study came up in conversation with a well-respected PS vendor, and he was fairly emphatic in his disagreement with the results. He felt that it (VSB) has to affect light performance in stones at least 2/3 of the time.
Since that''s not my area of training, I didn''t debate and we moved on.
Like any other highly technical field, experts can and do disagree from time to time, and in those cases the answer is somewhere short of absolute.
Date: 6/22/2010 4:27:20 PM
Author: Allison D.
Stone, the history of ACAs not allowing fluorescence has more to do with ''purist'' roots (which I know John has alluded to previously) than with performance. Most would agree that fluorescence in the faint to medium range doesn''t impact performance, and yet it wasn''t allowed in the ACA brand at all.
This is my gut feeling as well based on what I know about the brand and brands in general.
And more generally, of course a brand is free to make any rules it likes about what is allowed and what is not allowed, as does Tiffany wrt clarity and color in addition to flour. But none of these brand preferences offer proof positive that a given characteristic -- be it SI2 or J color or SB flour -- is "bad" overall and should be avoided, nor should such preferences be taken as proof of the benefit or costs of those characteristics.
As Wink''s commented, it''s been a tough haul and long curve in trying to move people away from negative connotations they''ve associated with fluorescence. It''s easy to see why it might make more sense to just avoid the issue altogether by disallowing it than the spend a huge amount of time trying to change people''s minds.
Especially since, ultimately, "the diamond industry" (whoever these people are) has nothing to gain from educating the public about flour -- why should the industry in general care if people are misinformed about flour, or color, or clarity or anything else? Misinformed consumers are easy to sell to, and that might be a positive to many diamond vendors. Present company excluded of course.
Me,
At least one forum goer I helped can see VS2 inclusions in her round cut, IIRC it was a JA stone GIA graded, and she has to do a return and get a VS1. So eye-clean is also dependent on individual''s eye-sight, so that is an arbitrarily cut off.Date: 6/22/2010 4:50:15 PM
Author: Isabelle
I have never, ever, ever seen a VS2 graded by GIA or AGS that had an eye visible inclusion. I can''t imagine a round brilliant VS2 with an inclusion you could see. I guess it could be possible with a less faceted cut though. It might interest you to know that Tiffany & Co. (AKA ''the McDonalds of the diamond industry'' LOL)recommends a higher clarity grade than VS2 for Emerald cuts for example.
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I am still going to say that the idea of seeing a flaw without 10X magnification in a VS 2 RB sounds pretty miraculous. Whomever has such eyes, (as opposed to a faulty grading report), really ought to consider herself quite fortunate.
Date: 6/22/2010 5:31:22 PM
Author: Isabelle
Noted. Thank you.
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