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Another Fluorescence ques....in bars/clubs

Dreamer_D

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Date: 6/21/2010 6:59:46 PM
Author: Isabelle
Hi Dreamer! I respect Stone''s knowledge but I have to say that I have read literature from very respected parties that claims strong fluor does negatively affect a diamond''s appearance. So at a minimum, experts disagree on the negative effect of fluor on the diamond''s appearance. Everyone seems to agree that it hurts the diamond''s value in the market. To me, those are red flags. But I''m happy to acknowledge that any given diamond can only really fairly be evaluated with the eyes since John, David and Stone all say these diamonds can be beautiful, again depending on the stone in question.
This topic has come up before and not a single PS expert has ever said that flour negatively affects optics in all but the *most rare* cases.
 

yssie

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Date: 6/21/2010 7:21:40 PM
Author: Isabelle
If you google 'strong fluorescence diamond value' I'm sure you'd find quite a lot of literature on it. But I have a source at home I'll put on here when I return. Tonight or tomorrow. :)
Googled it many times, have yet to see anything I'd consider remotely reliable supporting an objective statement that fluoro is always a 'negative' quality in a diamond.


Looking forward to seeing your paper.
 

elle_chris

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Date: 6/21/2010 6:44:48 PM
Author: dreamer_d


Even in strong sublight a SBF diamond does not really look blue. The appearance in the photo Jon posted is under black light and you really never seen that in any natural lighting environment. Besides, diamond don't really sparkle in direct sunlight, they will exhibit fire, and I cannot image flour affecting fire since it affects body color of the diamond not the refraction of light.

If a buyer cares about market value when buying a diamond, then they should only buy D-IF stones
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I think considering market value when buying a diamond is focussing on the wrong thing.

As to this comment: ' I don't see a connection between untrained salespersons and the value of strong fluorescent diamonds on the open market. They aren't worth as much, all other aspects being equal.--that's my main point---and the reason is b/c they can look cloudy at times.' The point that Stone is making is that the reason they are worth less than non flour stones is NOT because of the hazy oily issue. It is because of marketing and the change in diamond selling that happened in the 70s. It is not an inherent characteristic of blue flour that makes it less valuable.

This issue matters because in my opinion, informed consumers should be looking to get the best value of their money -- value meaning paying a fair price for the goods the receive. If the market is discounting certain diamonds because of irrelevant factors like marketing, or marking them up as well in the case of IF for example, then I think it is important for consumers to know that these intangibles are out there and know how they affect pricing so we do not get duped into paying for things that do not have a meaningful effect on the diamond's beauty and optics. I suppose if a buyer values those culturally dictated intangibles, then more power to them. But they should know the facts before they spend their money and know exactly what they are paying for.
Dreamer, I agree with everything you've said except for the part I highlighted. Don't know how strong the fluorescence would need to be, but the stone i saw on my colleague, outside in sunlight looked bluish. It didn't look like my diamond with medium fluoro.
Before seeing that, I never thought twice about fluoro. I could take it or leave it. Even now, I have no problem with diamonds with faint or medium fluoro. because I haven't noticed it. But if I can see it, I'd rather not have it.
 

Allison D.

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Date: 6/21/2010 10:39:37 AM
Author: John Pollard

The trade has an old history of discounting fluorescent diamonds which continues even though GIA debunked the myth that fluorescence was deleterious over a decade ago [GIA study with more photos]. In fact there are many enthusiasts who seek fluorescent diamonds because they love the effect.
To add on to John's comment, I'm not sure it was always the case but to the extent there is a bit of discounting for fluorescence in recent years, it's more prevalent in the colorless end of the market and is nil to negligible is the lower color ranges.

ETA: Shame on me for not reading everything before posting to catch that Todd had already mentioned this too.
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Dreamer_D

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Date: 6/21/2010 7:34:36 PM
Author: elle_chris
Dreamer, I agree with everything you''ve said except for the part I highlighted. Don''t know how strong the fluorescence would need to be, but the stone i saw on my colleague, outside in sunlight looked bluish. It didn''t look like my diamond with medium fluoro.
Before seeing that, I never thought twice about fluoro. I could take it or leave it. Even now, I have no problem with diamonds with faint or medium fluoro. because I haven''t noticed it. But if I can see it, I''d rather not have it.

Interesting. What color was the diamond? I suppose one''s definition of "blue" can vary, just as one''s definition of "tint" can too.


Still, this is an issue of perception and personal preference rather than a tangible detriment to the diamond''s optics.

 

Allison D.

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Date: 6/21/2010 7:27:24 PM
Author: dreamer_d

This topic has come up before and not a single PS expert has ever said that flour negatively affects optics in all but the *most rare* cases.
I can say that I know at least one who *has* said so.......but not publicly on PS.

Like many issues, even top-flight experts in a field can and do disagree.
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Isabelle

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Not all diamond experts are on PS though Dreamer. :) I''m not an expert. I''m not in the trade. But I''ve read literature that says strong blue fluor negatively impacts a diamond''s appearance. I restate that I accept and believe there are diamonds with strong fluor that look great. Maybe some day the presence of strong fluor won''t hurt a diamond''s value on the market, as Stone suggested. But it has for the last 40 years so it''s out there. And there are experts who say it does matter.
 

Isabelle

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That isn''t what I wrote though, Yssie. I wrote that STRONG fluor impacts a diamond''s value in the market and is considered by some well-respected experts to diminish a diamond''s appearance. Sheesh. Did I mention that I don''t work for the trade? :) I''m only stating what''s out there regarding strong fluor and very strong fluor. If it were considered a positive then it''s presence in a colorless diamond would cause the price to increase not decrease. I do think Dreamers point about fluor helping a warmer color stone could be spot on. (Dreamer wrote that in another thread about a week ago). :). For upper end retailers who don''t carry warm stones, J and the like, it really doesn''t matter though since that''s outside their wheelhouse in terms of what they will sell. IOW, the helpfulness of fluor in such a colored stone would be irrelevant to sales of colorless or near colorless diamonds where the presence of strong or very strong fluor is viewed negatively.
 

yssie

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My apologies - insert the word "strong" into my earlier statement, if you would.

I'm not trying to attack you or your opinions. I want to read what these experts you have found have to say, and to see whether they can back their claims scientifically. There's a lot of "do this, do that" out there, but so few stop to consider what fluoro actually is, and detail why those recommendations might have a basis in the optics, and I would love to see substantiation of the various opinions.
 

elle_chris

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Dreamer- no idea what the color is. she never said and i never asked. but the blue was noticeable, especially compared to mine.
 

Isabelle

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Date: 6/21/2010 8:15:42 PM
Author: yssie
My apologies - insert the word ''strong'' into my earlier statement, if you would.


I''m not trying to attack you or your opinions. I want to read what these experts you have found have to say, and to see whether they can back their claims scientifically. There''s a lot of ''do this, do that'' out there, but so few stop to consider what fluoro actually is, and detail why those recommendations might have a basis in the optics, and I would love to see substantiation of the various opinions.

Ok I am back home now. The insertion of the word "strong" really matters, b/c medium or faint fluorescence doesn''t have any bearing on a diamond''s value in the market. But, here is a quote from a book I had from Tiffany & Co. entitled A Tiffany Diamond Ring The Gemological Standards for Superlative Brilliance: "Beware of Excessive Fluorescence" is the title to the section. "Certain diamonds exhibit a natural phenomenon that makes the stone glow when exposed to ultraviolet light. In certain store light this fluorescence can actually mask the color of a diamond, making it appear whiter than it really is. However, in natural light, intense fluorescence produces a diamond with a disappointing milky appearance. Tiffany will not accept diamonds that our Gemological Laboratory determines to have ''strong'' or ''very strong'' fluorescence."

Now, either Tiffany has just arbitrarily created an issue where there is none, and they are engaged in libel for writing that these diamonds are less valuable when in fact they are actually MORE valuable, OR Tiffany is making a claim that has been widely accepted by the industry to be factual. I vote for Option 2. But again, I readily acknowledge that there could be many stones with strong fluorescence that don''t look milky. But clearly there are experts out there who think it''s a problem. Otherwise, these stones would be worth as much as their non-fluorescent counterparts. Oh, and I found this on Pricescope: "We advise you not to buy a Very Strong unless you can actually see the diamond side by side with non-fluorescent diamonds in shaded daylight (which has a lot of UV light) or with a UV filter like a small sheet of Lexan." So again, if the consumer can see the diamond himself or herself and in different lighting scenarios then I would defer to John and David and agree that it is totally possible that the diamond could look fantastic, even if it isn''t worth as much.
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Rockdiamond

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Interesting conversation- great points Isabel.
I would say that Tiffany, as a rule, is attempting to distance themselves from everyone else.
I do not believe Cartier or Winston have similar policies- for example. Forgetting about the rest of the mere mortal sellers.

But there's no question a statement like Tiffany's is marketing mixed with factual info.
They use the qualifier "Certain Diamonds"

Remember, J-K color stones may actually trade for sightly more with Medium, or even strong blue- if it's the type that makes the stone look more white with no dulling. But that rules Tiffany out as I believe I is their minimum
 

Isabelle

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Date: 6/21/2010 11:52:10 PM
Author: Rockdiamond
Interesting conversation- great points Isabel.

I would say that Tiffany, as a rule, is attempting to distance themselves from everyone else.

I do not believe Cartier or Winston have similar policies- for example. Forgetting about the rest of the mere mortal sellers.


But there''s no question a statement like Tiffany''s is marketing mixed with factual info.

They use the qualifier ''Certain Diamonds''


Remember, J-K color stones may actually trade for sightly more with Medium, or even strong blue- if it''s the type that makes the stone look more white with no dulling. But that rules Tiffany out as I believe I is their minimum


Yes, I wrote that in an earlier post as well. They won''t sell J stones so the helpfulness of fluor is a non-issue with them. I am not as familiar with Cartier''s standards for fluorescence. I think your observation that it is just so helpful to see the stone yourself is really quite spot on. And if you cannot see it yourself, then buy from a vendor whom you really feel you can trust.
 

Lula

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Date: 6/21/2010 11:34:42 PM
Author: Isabelle
Date: 6/21/2010 8:15:42 PM

Author: yssie

My apologies - insert the word 'strong' into my earlier statement, if you would.



I'm not trying to attack you or your opinions. I want to read what these experts you have found have to say, and to see whether they can back their claims scientifically. There's a lot of 'do this, do that' out there, but so few stop to consider what fluoro actually is, and detail why those recommendations might have a basis in the optics, and I would love to see substantiation of the various opinions.


Ok I am back home now. The insertion of the word 'strong' really matters, b/c medium or faint fluorescence doesn't have any bearing on a diamond's value in the market. But, here is a quote from a book I had from Tiffany & Co. entitled A Tiffany Diamond Ring The Gemological Standards for Superlative Brilliance: 'Beware of Excessive Fluorescence' is the title to the section. 'Certain diamonds exhibit a natural phenomenon that makes the stone glow when exposed to ultraviolet light. In certain store light this fluorescence can actually mask the color of a diamond, making it appear whiter than it really is. However, in natural light, intense fluorescence produces a diamond with a disappointing milky appearance. Tiffany will not accept diamonds that our Gemological Laboratory determines to have 'strong' or 'very strong' fluorescence.'


Now, either Tiffany has just arbitrarily created an issue where there is none, and they are engaged in libel for writing that these diamonds are less valuable when in fact they are actually MORE valuable, OR Tiffany is making a claim that has been widely accepted by the industry to be factual. I vote for Option 2. But again, I readily acknowledge that there could be many stones with strong fluorescence that don't look milky. But clearly there are experts out there who think it's a problem. Otherwise, these stones would be worth as much as their non-fluorescent counterparts. Oh, and I found this on Pricescope: 'We advise you not to buy a Very Strong unless you can actually see the diamond side by side with non-fluorescent diamonds in shaded daylight (which has a lot of UV light) or with a UV filter like a small sheet of Lexan.' So again, if the consumer can see the diamond himself or herself and in different lighting scenarios then I would defer to John and David and agree that it is totally possible that the diamond could look fantastic, even if it isn't worth as much.

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I'm trying not to pull out my hair here. If the "experts" you've referred to in your numerous posts on this thread is one expert, and that one expert is Tiffany, well....consider the source. Many retailers set arbitrary standards for color and clarity grades that they won't got below. Why? It tricks consumers into believing diamonds of higher color and clarity are better looking and sparkle more than diamonds "below" their arbitrary cut-offs. Why would a retailer do this? Well, they can make more money on stones that have higher clarity and color grades. Here at PS we know it's the cut that influences sparkle, not color and not clarity, and, not, I'm sorry, fluorescence.

Does this mean that there is not misinformation out there about the effect of color, clarity, and fluorescence on the "sparkle" of the diamond? No, misinformation abounds. In fact, just recently a jeweler who has been in business for over 30 years told me that a VVS2 stone she was showing me will sparkle more than one that has a lower clarity grade. When I asked her about the cut being not so good because the stone was quite deep, she flat out disagreed with me, and told me from her longtime experience in the business (ahem -- the expert!) that it was a finely cut stone. Fine. Whatever. I left the thinking, lady, I will never buy from you because you will never have credibility with me.

There are many "experts" in this field -- and in other fields -- who do not keep up with the latest education in the field. There is no requirement that I know of that requires that jewelers obtain continuing education (like doctors and lawyers, and even barbers). So it is up to the individual jeweler to seek out educational opportunities to stay abreast of changes and improved technology and knowledge in the field. I'd be willing to bet that the vast majority of jewelers in business today are operating on myths and misinformation from 30+ years ago. I don't know about you, but I don't go to doctors who are using medical technology that is 30 years old.

While it is true that a de minimis number of diamonds may show negative effects due to SBF or VSBF, the number is so small as to be meaningless, statistically speaking. To try to make that number meaningful by repeating over and over that there are experts that say all stones that have SBF or VSBF are undervalued and cloudy is simply misleading.

Again, each retailer has the right to determine the color-clarity-fluoro benchmarks for what they choose to sell. That's about preference -- their own and their customers' preferences. But to link personal preference with value and beauty is a jump I am unwilling to make, because I know it is cut* that makes a diamond beautiful -- the rest is just personal preference (and more or less money in the jeweler's pocket).

ETA: Libel is difficult to prove, and the courts have historically allowed sales people a certain amount of "puffery" or exaggeration in their claims. Often this puffery is an appeal to the customer's emotions or need for status. But it doesn't make what they say true just because they have the right to say it!

*ETA: I am not speaking of just H&A RB's here; well-cut stones come in many "flavors."
 

Isabelle

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Date: 6/22/2010 12:11:28 AM
Author: sarap333
Date: 6/21/2010 11:34:42 PM

Author: Isabelle

Date: 6/21/2010 8:15:42 PM


Author: yssie


My apologies - insert the word ''strong'' into my earlier statement, if you would.




I''m not trying to attack you or your opinions. I want to read what these experts you have found have to say, and to see whether they can back their claims scientifically. There''s a lot of ''do this, do that'' out there, but so few stop to consider what fluoro actually is, and detail why those recommendations might have a basis in the optics, and I would love to see substantiation of the various opinions.



Ok I am back home now. The insertion of the word ''strong'' really matters, b/c medium or faint fluorescence doesn''t have any bearing on a diamond''s value in the market. But, here is a quote from a book I had from Tiffany & Co. entitled A Tiffany Diamond Ring The Gemological Standards for Superlative Brilliance: ''Beware of Excessive Fluorescence'' is the title to the section. ''Certain diamonds exhibit a natural phenomenon that makes the stone glow when exposed to ultraviolet light. In certain store light this fluorescence can actually mask the color of a diamond, making it appear whiter than it really is. However, in natural light, intense fluorescence produces a diamond with a disappointing milky appearance. Tiffany will not accept diamonds that our Gemological Laboratory determines to have ''strong'' or ''very strong'' fluorescence.''



Now, either Tiffany has just arbitrarily created an issue where there is none, and they are engaged in libel for writing that these diamonds are less valuable when in fact they are actually MORE valuable, OR Tiffany is making a claim that has been widely accepted by the industry to be factual. I vote for Option 2. But again, I readily acknowledge that there could be many stones with strong fluorescence that don''t look milky. But clearly there are experts out there who think it''s a problem. Otherwise, these stones would be worth as much as their non-fluorescent counterparts. Oh, and I found this on Pricescope: ''We advise you not to buy a Very Strong unless you can actually see the diamond side by side with non-fluorescent diamonds in shaded daylight (which has a lot of UV light) or with a UV filter like a small sheet of Lexan.'' So again, if the consumer can see the diamond himself or herself and in different lighting scenarios then I would defer to John and David and agree that it is totally possible that the diamond could look fantastic, even if it isn''t worth as much.


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I''m trying not to pull out my hair here. If the ''experts'' you''ve referred to in your numerous posts on this thread is one expert, and that one expert is Tiffany, well....consider the source. Many retailers set arbitrary standards for color and clarity grades that they won''t got below. Why? It tricks consumers into believing diamonds of higher color and clarity are better looking and sparkle more than diamonds ''below'' their arbitrary cut-offs. Why would a retailer do this? Well, they can make more money on stones that have higher clarity and color grades. Here at PS we know it''s the cut that influences sparkle, not color and not clarity, and, not, I''m sorry, fluorescence.


Does this mean that there is not misinformation out there about the effect of color, clarity, and fluorescence on the ''sparkle'' of the diamond? No, misinformation abounds. In fact, just recently a jeweler who has been in business for over 30 years told me that a VVS2 stone she was showing me will sparkle more than one that has a lower clarity grade. When I asked her about the cut being not so good because the stone was quite deep, she flat out disagreed with me, and told me from her longtime experience in the business (ahem -- the expert!) that it was a finely cut stone. Fine. Whatever. I left the thinking, lady, I will never buy from you because you will never have credibility with me.


There are many ''experts'' in this field -- and in other fields -- who do not keep up with the latest education in the field. There is no requirement that I know of that requires that jewelers obtain continuing education (like doctors and lawyers, and even barbers). So it is up to the individual jeweler to seek out educational opportunities to stay abreast of changes and improved technology and knowledge in the field. I''d be willing to bet that the vast majority of jewelers in business today are operating on myths and misinformation from 30+ years ago. I don''t know about you, but I don''t go to doctors who are using medical technology that is 30 years old.


While it is true that a de minimis number of diamonds may show negative effects due to SBF or VSBF, the number is so small as to be meaningless, statistically speaking. To try to make that number meaningful by repeating over and over that there are experts that say all stones that have SBF or VSBF are undervalued and cloudy is simply misleading.


Again, each retailer has the right to determine the color-clarity-fluoro benchmarks for what they choose to sell. That''s about preference -- their own and their customers'' preferences. But to link personal preference with value and beauty is a jump I am unwilling to make, because I know it is cut that makes a diamond beautiful -- the rest is just personal preference (and more or less money in the jeweler''s pocket).

I will only repeat that there are many experts, including the article I quoted from THIS WEBSITE that say in effect "Don''t buy it" or "Don''t buy it without seeing it in certain conditions first." I don''t know what "consider the source" is about in your sentence about Tiffany and Co. They are an outstanding source for excellent quality and their standards are widely respected. They hold patents on two different diamond cuts and an exclusive license to market a third patented cut. But if it will keep you from pulling your hair out, I am willing to pretend they don''t know anything about quality diamonds so that we can all agree with the notion that very strong fluorescence is not only a good thing, it''s actually preferred in the industry. ;-)
 

yssie

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...
 

yssie

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Isabelle, I'm not sure what to say. Tiffs also does not sell SI2s. Or any colour below I, doesn't mean that's not an arbitrary cutoff too.


Sara, I reckon I'm joining you

pullhair.jpg
 

Dreamer_D

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I do not consider Tiffany''s to be a source of pure unbiased information about diamonds.

I also do not consider McDonald''s to be to be a source of pure unbiased information about nutrition.
 

Dreamer_D

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And I sought out the place on PS where flour is discussed in the knowledge section. For completeness, I have posted highlights below that add context to the quote that Isabelle posted previously. I think that it is fairly obvious that PS is not suggesting not to buy VSBF diamonds. Emphasis added by moi.

*****

[snip]

But the most likely reason for fluoro diamond discounting is because of the sad fact that many jewellery salespeople are not able to explain complex phenomena like fluoro; a Fluoro (or any comments) written on a report makes the diamond harder to sell = worth less! Sales killing explanation: Fluorescence is visible light emitted by electrons when a diamond is excited by higher energy source (Ultra Violet light or X-rays).

Some diamonds have extremely strong fluorescence and appear oily or cloudy like the one in the picture below. This is BAD. But the GIA study found them to be very rare; they were unable to find enough cloudy stones to do a study from the 26,010 sample they used.



[snip]

Note that diamonds usually appear quite dark when seen in direct sunlight; a fact that terrify's and frightens many first time diamond buyers. Since no diamond looks really good in direct sunlight, the fact that some fluorescence diamonds get a bluish blush should not be a big deal. There are usually only very few very strong sparkles in direct sunlight, and relative darkness in the body of the diamond – and it is this effect that often shocks people the first time they see their new diamond in sunlight.

Fluorescence is not generally an issue other than also being a fun feature in its own right.



We advise you not to buy a Very Strong unless you can actually see the diamond side by side with non-fluorescent diamonds in shaded daylight (which has a lot of UV light) or with a UV filter like a small sheet of Lexan. My experience from the sales floor is confirms the GIA findings; most people would choose a fluorescent diamond over a non stone anyway. And lots of diamantaires and trade people actually seek them out. The fact it may cost less is a real bonus.



[snip]

 

Circe

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Isabelle, there''s received wisdom, and then there''s research. Yes, it''s a good idea to see stones in person, but it goes just as much for the rare VS2 that has an eye-visible inclusion or the unusually low G with an offensive tint as it does for the fluorescent stone that''s discernible to the naked eye under normal viewing conditions. If it''s one slightly self-serving booklet vs. a bunch of industry professionals and disinterested passionate hobbyists waving peer-reviewed literature around, maybe there''s something to the other side?

P.S. - Not aimed at you specifically, but fights online always make me think of this:

duty_calls.png
 

Isabelle

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Date: 6/22/2010 12:49:08 AM
Author: yssie
Isabelle, I''m not sure what to say. Tiffs also does not sell SI2s. Or any colour below I, doesn''t mean that''s not an arbitrary cutoff too.



Sara, I reckon I''m joining you

Actually,that''s not arbitrary either. They don''t sell stones with inclusions that are visible to the naked eye or a standard loupe. I have an SI1 and I can see the inclusion.
 

Isabelle

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Date: 6/22/2010 1:08:53 AM
Author: dreamer_d
I do not consider Tiffany''s to be a source of pure unbiased information about diamonds.


I also do not consider McDonald''s to be to be a source of pure unbiased information about nutrition.

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.
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Isabelle

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Date: 6/22/2010 1:15:40 AM
Author: dreamer_d
And I sought out the place on PS where flour is discussed in the knowledge section. For completeness, I have posted highlights below that add context to the quote that Isabelle posted previously. I think that it is fairly obvious that PS is not suggesting not to buy VSBF diamonds. Emphasis added by moi.


*****


[snip]


But the most likely reason for fluoro diamond discounting is because of the sad fact that many jewellery salespeople are not able to explain complex phenomena like fluoro; a Fluoro (or any comments) written on a report makes the diamond harder to sell = worth less! Sales killing explanation: Fluorescence is visible light emitted by electrons when a diamond is excited by higher energy source (Ultra Violet light or X-rays).


Some diamonds have extremely strong fluorescence and appear oily or cloudy like the one in the picture below. This is BAD. But the GIA study found them to be very rare; they were unable to find enough cloudy stones to do a study from the 26,010 sample they used.




[snip]


Note that diamonds usually appear quite dark when seen in direct sunlight; a fact that terrify''s and frightens many first time diamond buyers. Since no diamond looks really good in direct sunlight, the fact that some fluorescence diamonds get a bluish blush should not be a big deal. There are usually only very few very strong sparkles in direct sunlight, and relative darkness in the body of the diamond – and it is this effect that often shocks people the first time they see their new diamond in sunlight.


Fluorescence is not generally an issue other than also being a fun feature in its own right.




We advise you not to buy a Very Strong unless you can actually see the diamond side by side with non-fluorescent diamonds in shaded daylight (which has a lot of UV light) or with a UV filter like a small sheet of Lexan. My experience from the sales floor is confirms the GIA findings; most people would choose a fluorescent diamond over a non stone anyway. And lots of diamantaires and trade people actually seek them out. The fact it may cost less is a real bonus.




[snip]


Actually, I repeat again: Pricescope IS ADVISING, very directly, that "you not to buy a Very Strong unless you can actually see the diamond side by side with non-fluorescent diamonds in shaded daylight (which has a lot of UV light) or with a UV filter like a small sheet of Lexan." So, see it in natural daylight in person first. Or get a money back return guarantee.
 

Isabelle

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Date: 6/22/2010 1:25:38 AM
Author: yssie
Some interesting reading I meant to attach earlier, incl an older article so it would probably be wise to proof along the way
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http://lgdl.gia.edu/pdfs/W97_fluoresce.pdf


http://www.goodoldgold.com/4Cs/Color/Fluorescence/

http://en.wikipedia.org/wiki/Crystallographic_defects_in_diamond

Thanks Yssie! I read the GIA article! They didn''t get to study VSB fluor diamonds though, b/c to John''s point, they couldn''t find any. I hope they do more studies on it. A follow up would be great. Thank you again for posting the links.
 

Isabelle

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Date: 6/22/2010 7:42:07 AM
Author: Circe
Isabelle, there''s received wisdom, and then there''s research. Yes, it''s a good idea to see stones in person, but it goes just as much for the rare VS2 that has an eye-visible inclusion or the unusually low G with an offensive tint as it does for the fluorescent stone that''s discernible to the naked eye under normal viewing conditions. If it''s one slightly self-serving booklet vs. a bunch of industry professionals and disinterested passionate hobbyists waving peer-reviewed literature around, maybe there''s something to the other side?


P.S. - Not aimed at you specifically, but fights online always make me think of this:

LOL Circe! I love that cartoon! It''s great. BTW, I don''t think anyone is "wrong" for disagreeing with the trade on the value of strong or very strong fluor diamonds. The only thing that is wrong (to my mind) is the assertion that these diamonds are not controversial or that they trade for as much value as one without the strong or very strong fluor (all other aspects being equal). I am convinced by John, Stone and David that you can have a fluor diamond that looks remarkable. But as a CONSUMER, I would want a discount and I would want to see it in person in all sorts of lighting so that I could be really comfortable with the assertion that the fluor would not hinder the diamond''s appearance. I take Tiffany''s caution to heart in that you can''t judge just inside the store where the stone could appear whiter than it truly is in normal conditions, and that under normal conditions it might look milky. Not ALL of these stones would. Maybe not most of them would. But some would. And I wouldn''t want to buy one that did if I could help it.
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WinkHPD

Ideal_Rock
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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. :) Thank you John!
Just to point out that John was referring to overblues, the stones that look oily out of doors. These unpleasant looking stones trade at large disounts, unlike the small discounts of fluorescent stones that may or may not have a slight powder blue glow out of doors.

As has been stated above, stones that fluoresce with a beautiful glow used to sell for quite a premium, 5 - 15% was common with an occassional stone bringing 20% if it was particularly striking out of doors. I used to sell many of them during my early days in the industry.

Along came the investment craze of the late 70''s and the shoe clerks now selling diamonds in telephone sweat shops could not understand nor explain fluorescence, and heavens forbid they should ever actually take one outside to see it. It was easier to just discount fluorescent stones than to train the (insult to telemarketers deleted).

Add in the fact that chain stores like Zales needed to buy thousands of diamonds at a time and they did not want to have to go through parcels to pick out the possible overblues, so they also refused to take parcels that contained anything with more than weak fluorescence and you have the beautiful fluorescent stones taking a hit and getting a bad name.

I once went with John Pollard to do a diamond sales training at a wonderful store. During the training session I asked how many disliked fluoresccent stones. Many hands went up. I asked why and many of the same things said above, ie, unpleasant look out of doors, etc, were mentioned. When I asked how many had actually taken one of the stones outside to look at them, not one hand went up! During the course of the day I took the time to take one of their store''s VSB diamonds outside with each of the people who raised their hand about not liking them.

All were surprised by the look of the stone out of doors. It simply was NOT what they had been led to expect. I made no attempt to convince them to like the fluorescent stone, although I think I the stone itself might have convinced some of them, but at least now they had actually seen the fallacy of what they had been saying sight unseen.

RE: why did that other PSer say she was able to get a much larger stone by going with strong fluor?

Without seeing the diamond it would not be possible to know, but given the large difference in price versus the known 1 - 5% discount offered at the trade level, I am going to surmise that it might have had to due with some other factor, ie second hand stone, cutting quality, had the stone in house for years and needed to move it, etc. etc. I can only guess of course, since I know nothing of the stone, but I will guess that there were factors other than fluorescence involved

RE: Rock Diamond''s comment: ... statement about negative comments about fluorescence- no question such misinformation is out there. (bolding is mine)

Sadly, I complete concordance with this. It is amazing to me how much false information about such issues is touted as gospel in the jewelry trade. I can hear the planning session at Jewelers Misinformation Training now. "Hey, 99.5% of strongly blue fluorescent stones are beautiful and the rest vary in how ugly they are, we better warn the public away from all such stones and sell them all at a huge discount, especially the beautiful ones, just to be safe. Oh, and be sure not to tell them about the beautiful ones, we don''t want to confuse the issue!"

Sigh.

Wink
 

WinkHPD

Ideal_Rock
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Messages
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Date: 6/21/2010 7:54:47 PM
Author: Isabelle
Not all diamond experts are on PS though Dreamer. :) I''m not an expert. I''m not in the trade. But I''ve read literature that says strong blue fluor negatively impacts a diamond''s appearance. I restate that I accept and believe there are diamonds with strong fluor that look great. Maybe some day the presence of strong fluor won''t hurt a diamond''s value on the market, as Stone suggested. But it has for the last 40 years so it''s out there. And there are experts who say it does matter.

Small quibble, more like 32 - 34 years. We were still selling VSB diamonds at a premium in 1975, it was somewhat later, in the late 70''s that fluorescence became a negative. This actually became more universal with the start of the Rap report as he publishes a guide for the effect of fluorescence in his price list, although I am not sure when exactly he started to do that. The late seventies were a tumultuous time in our industry as the price for a one carat diamond that was graded by GIA to be D-IF went from (pricing approximate, I am old and my memory may not be exact) $2,500 per carat wholesale in 1972 to $65,000 per carat between dealers in the NY Diamond Buyer''s Club in Feb of 1980 only to fall back to about $15,000 per carat by June of 1980.

Tumultuous, but VERY VERY interesting!

Wink

P.S. The story of the Rapaport list and the death threats to Martin are another interesting part of this time period, and I imagine already covered somewhere in this wonderful forum.
 

stone-cold11

Super_Ideal_Rock
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Messages
14,083
Date: 6/22/2010 8:05:31 AM
Author: Isabelle
Date: 6/22/2010 1:25:38 AM

Thanks Yssie! I read the GIA article! They didn''t get to study VSB fluor diamonds though, b/c to John''s point, they couldn''t find any. I hope they do more studies on it. A follow up would be great. Thank you again for posting the links.
Wrong conclusion. They found enough VSB fluor, just not enough of these fluorescence stones are over-blue. Over blue can occur for stones strong and above. Just look at the tables in the GIA report.
 

WinkHPD

Ideal_Rock
Trade
Joined
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Messages
7,516
Date: 6/22/2010 8:10:39 AM
Author: Isabelle

Date: 6/22/2010 7:42:07 AM
Author: Circe
Isabelle, there''s received wisdom, and then there''s research. Yes, it''s a good idea to see stones in person, but it goes just as much for the rare VS2 that has an eye-visible inclusion or the unusually low G with an offensive tint as it does for the fluorescent stone that''s discernible to the naked eye under normal viewing conditions. If it''s one slightly self-serving booklet vs. a bunch of industry professionals and disinterested passionate hobbyists waving peer-reviewed literature around, maybe there''s something to the other side?


P.S. - Not aimed at you specifically, but fights online always make me think of this:

LOL Circe! I love that cartoon! It''s great. BTW, I don''t think anyone is ''wrong'' for disagreeing with the trade on the value of strong or very strong fluor diamonds. The only thing that is wrong (to my mind) is the assertion that these diamonds are not controversial or that they trade for as much value as one without the strong or very strong fluor (all other aspects being equal). I am convinced by John, Stone and David that you can have a fluor diamond that looks remarkable. But as a CONSUMER, I would want a discount and I would want to see it in person in all sorts of lighting so that I could be really comfortable with the assertion that the fluor would not hinder the diamond''s appearance. I take Tiffany''s caution to heart in that you can''t judge just inside the store where the stone could appear whiter than it truly is in normal conditions, and that under normal conditions it might look milky. Not ALL of these stones would. Maybe not most of them would. But some would. And I wouldn''t want to buy one that did if I could help it.
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Ditto! Called my wife in to see it.

Here I am in agreement with you. You should indeed want to see all diamonds that you buy, fluorescent or not. That is why most internet vendors have strong return policies so that our clients can comfortably examine stones without undue time constraints. I don''t have my last Rap report hand, but the discounts are typically in the 1-5% range depending on the color and of course becoming price increases at the lower colors. In the rare case of an overblue, the discounts will be huge compared to a normally fluorescent diamond.

Wink
 
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