Should we discourage or recommend FL stones?

[Texas Leaguer]

David, I am really not sure what you are trying to accomplish in this thread. We have already agreed that the answer to your subject line is that we should not discourage or recommend fluorescent diamonds. We should instead educate.

It is well established here that you feel that you have personally seen 'countless' diamonds that look whiter than their color grade in normal lighting due to fluorescence. That is one data point for people to consider.

They may also consider how much credence to put into that statement given what we know scientifically about the conditions under which fluorescence is activated in a diamond. And, for that matter, what GIA says about it based on their surveys.

It is certainly true that many diamond dealers have for decades promoted this benefit. Whether that is a notion deriving from salesmanship or some verifiable fact is in question. But it has caused a certain amount of trade 'group think' that has momentum of its own.

From an education and consumer protection perspective, my point is that shoppers should not base their purchase decision on this dubious benefit. And conversely, that they should not be dissuaded from an otherwise great diamond just because it glows under a black light.

 

[Rockdiamond]

Rockdiamond, it might be enlightening for consumers to better understand your estimate of the percentage of just the dealers you know who strongly resist or avoid buying diamonds with more than slight UV fluorescence.

Hi David!!!
As usual, you've added valuable content to a discussion.
When it comes to buying- the folks with cash on hand ready to snap up distressed merchandise are different than diamond dealers. These are people who will buy basically any diamond, as long as the price is right. If D/IF no blue is $10k wholesale, they will offer $7k+-. Under this scenario, a D/IF SB is wholesale at $8k- cash buyers are interested at $5500+-. If the stone is badly made ( bad cut) maybe $3500.
These guys and gals will buy anything
It's only about price.

Do you think that this widespread tendency of the way dealers react to UV fluorescence is pretty much the norm in spite of any arguments we might make here? Do you see any move from your traditional dealer buddies to greet fluorescent diamonds in a more generous or understanding manner? You may be personally liberal after all your exposure to Pricescope for so long, but I believe you would be exceptional among the majority of dealers. I see this issue mostly as a battle over tradition, not a battle based on scientific facts. What do you think?

The NYC market has changed quite a bit over the past 20 years. There used to be many more people with diamonds in their blood- people who grew up in the industry. Many of those are gone, and foreign-based cutters now dominate the market. Primarily Indian. They generally employ younger people to represent them here in NYC. Nice people but not truly what we'd call diamond experts a la Pricescope. In many cases, I can't really get an idea what a diamond looks like by speaking to them, as I could have if I was speaking to one of my buddies from the Winston days. Most dealers will tell you every stone they have is the best thing since sliced bread.

But the people putting the prices on the goods in India ( and the few NY dealers who are still important) understand the market to the last penny.
Higher colors with fluorescence are discounted as compared to inert stones in virtually all cases- however, you will find J-K-L color stones with MB or even SB that trade at equivalent- or even higher prices than inert stones of the same grades/sizes.
So, it's tradition, as well as physical characteristics, which must be observed first hand that determine the prices. We can howl at the moon here on PS about science... it ain't going change diamond prices which are based on the physical reality of how a given diamond looks in person.

 

[Rockdiamond]

Bryan- I never intended, nor did I wish to debate the point on which we disagree. I regret that the discussion took that turn. In retrospect, I never should have mentioned it.
How would this sound, as a way to put it:
If a diamond dealer says he has a J color that looks better due to fluorescence, by no means blindly accept that as a fact- but nor should a buyer automatically reject that notion.
How's that?

I started the discussion for a number of reasons..
Primarily the fact that when we actively discuss things, people get engaged, and are more likely to actually learn things.

 

[arkieb1]

Two points;
The first is that it negatively impacts some diamonds, I've seen one that looked like it was oily and straining to sparkled in EVERY lighting situation.... People that are new that want to buy a diamond off a website or virtual inventory frequently can't see the diamond beforehand in person. Vendors do not generally disclose if the fluorescence has any negative impacts on the diamond or not. They should. Sites now state if diamonds are eye clean or not, so disclose if the fl makes a diamond look blaaah or not.

Second point we all know that in general diamonds with strong and moderate fl on places like RapNet etc are cheaper than stones without it, again buyers tend to go for these diamonds because they are cheaper ie represent better dollar value, there is a big issue when some vendors don't pass on the savings and when they don't disclose how badly impacted some of these stones might be, which is why they are significantly cheaper than everything else....

 

[JPie]

To answer the question, neither. Give customers the facts so they can make educated decisions for themselves.

 

[Texas Leaguer]

Two points;
The first is that it negatively impacts some diamonds, I've seen one that looked like it was oily and straining to sparkled in EVERY lighting situation.... People that are new that want to buy a diamond off a website or virtual inventory frequently can't see the diamond beforehand in person. Vendors do not generally disclose if the fluorescence has any negative impacts on the diamond or not. They should. Sites now state if diamonds are eye clean or not, so disclose if the fl makes a diamond look blaaah or not.

Strong fluorescence can make a diamond look hazy and oily. However, if a diamond has compromised transparency in EVERY lighting situation, there is probably something else going on. Graining, twinning wisps and clouds are the usual suspects. If haziness is present in lighting with insufficient UV intensity to stimulate fluorescence, then the fluoro is not the culprit.

 

[Rockdiamond]

Bryan- I have seen countless stones that are overblue and dull due to it. This is related to, but totally different than a discussion on the potential for face up color improvement in desirable fluorescent diamonds.
We routinely work through large parcels of fancy colored diamonds. Literally hundreds of carats of .10-.50ct stones in parcels. Pink diamonds, in particular, have a higher percentage of fluorescent stones than other colors we see.
Plenty of cases where an ultra strong fluorescent stone is clean, but dull. No matter where you look at it- as long as there's enough light to allow for close examination.


@arkieb1 - apparently we've had similar experiences with dull fluorescent diamonds.
Your point about sellers being able to answer questions about the specifics of fluorescence when they now seem to be able to answer the "eye clean" question....
The reason is that the wholesale database now has a data box called "eye clean"...so the cutter, or seller who actually has the diamond can make that determination and share it.
It would be a great suggestion to Rappaport to include "dull?" as a data entry box....

 

[TODiamonds]

We're talking in circles about different topics here.

Whether a diamond may or may not face up whiter due to fluorescence is a whole different can of worms. I personally think it is foolish to buy a fluo diamond with the expectation that it will improve the face up color - but to each their own. We should drop this particular debate because there clearly isn't any consensus within this forum (or the broader community for that matter) and more importantly there's no meaningful scientific evidence out there to back up any of your positions anyway.

I really think the key point here - and the reason why this thread was originally started - was because I felt many people often do users a disservice by referencing that old GIA study (the 0.2% one) - as a means to encourage people to freely buy fluorescent stones, when the reality is the actual % of hazy stones is much higher. Whether that's 10%, 20%, 50% depends on who you ask, but it is a real issue, and users on this forum should know that before dropping their hard earned bucks on strong/very strong Fluo.

If there's anything to take away from this thread let it be that.

 

[kenny]

We're talking in circles about different topics here.

Whether a diamond may or may not face up whiter due to fluorescence is a whole different can of worms. I personally think it is foolish to buy a fluo diamond with the expectation that it will improve the face up color - but to each their own.

How wrong you are!
There is consensus in science regarding fluorescence in diamonds.

Unfortunately we now live in a world, well in a country, where enough people poopoo science, education, and even intelligence itself, that they were able to elect a president.

Apparently the new PC paradigm is, the opinion of everyone from Oxford Ph.Ds to kindergarten dropouts, is equal.




But hey, these people buy diamonds too so maybe a seller who comes across as anti-science, anti-intelligence, and anti-status quo will end up selling zillions of diamonds to this demographic.
Hmmmmm.

Fluor is activated by light that has enough ultraviolet content.
Not all light does.
Nearly all indoor artificial light has little or no UV.
Next you must educate that fluor comes in many colors, but only blue can help a diamond look less yellow, and only in light that has adequate UV, including sunlight.


Telling someone, ESPECIALLY A BUYER IF YOU ARE A SELLER, that fluor makes a J look more white even indoors is wrong, dishonest, unethical and should be called out at PS.
Any seller who posts this or tells this lie to their customers should be permanently banned from PS.

PS is about truth in diamond education.
Not maximizing profit with lies.

This toxic misinformation should not get a pass as "diversity of opinion" any more than today stating the world is flat.
Once again

 

[arkieb1]

Strong fluorescence can make a diamond look hazy and oily. However, if a diamond has compromised transparency in EVERY lighting situation, there is probably something else going on. Graining, twinning wisps and clouds are the usual suspects. If haziness is present in lighting with insufficient UV intensity to stimulate fluorescence, then the fluoro is not the culprit.

It was a GIA graded G coloured VS1 clarity stone. There was nothing else going on in it, I saw the certificate - but I have eagle eyes compared to normal people once I saw the fluorescence I couldn't unsee it. It looked oily and straining to sparkle no matter what lighting you put it in.

For the record my mother has a diamond that has fluorescence and it is not negatively impacted by it. It's a pretty stone. It has a slight blue tint out in strong Aussie sunlight.

@Rockdiamond - yes I guess RapNet should add that, something like slight haze perhaps? I always assume that when the price is "too good to be true" there is some underlying factor why. I was more suggesting that in the interests of transparency (no pun intended) that big retail vendors like WF and BN should be listing if a diamond is impacted by things like surface and internal graining and fluorescence. If they can list if a stone is eye clean surely they can list if it is hazy or not, that way when a consumer unfamiliar with diamonds goes for the cheapest of the bunch and it is eye clean but it might have other issues, they know what they are really getting.

I have always been fascinated by Brian Gavin's strategic choice to cut and sell diamonds with fluorescence at a premium price because of cut. Many decades ago you couldn't give these stones away, now with some clever marketing proof you can charge a premium for them and market anything as worth buying.

 

[Rockdiamond]

Whoever is claiming this scientific proof exists- please show it to us.
The best we have from GIA is non conclusive. And that’s after a study of a “ four sets of round diamonds”
We don’t know the specifics. Other shapes were not studied.
So where is this science.
Kenny, I share your distress at the denying of established science. All my kids are vaccinated. Given that I’ve spent over 45 years studying and working and teaching people about diamonds,I’d really be interested if there was established science on this. There isn’t.

I’ve seen J color stones that faced up whiter than other J stones due to fluorescence. I’ve also seen D color stones that looked super blue white due to fluorescence.
I’ve sold diamonds to people after describing these effects. Kenny, for some reason you’re heck bent on attacking my character. I live in a world where my word is my bond.
Cool thing about the internet- if a seller lies and cheats people, it’s going to come out.
But again- this isn’t about me- it’s about assisting consumers in understanding the complexities of fluorescence.
A seller who is looking at a diamond, and describing these effect is not necessarily lying.

 

[monipod]

I won’t ever make blanket statements about how fluorescence affects a particular diamond that I’ve never seen.

I'm an absolute novice in regards to diamond aesthetics but being a complete science nerd, fluorescence just amazes me... I'm still in search of a strong blue for the fun of it.

If I look at a listing of completed diamond rings on the James Allen website, the stones I feel might have fluorescence turn out to be D/E/F colour. I guess they have that tinge when photographed under UV lighting. I doubt I'd be able to notice fluorescence in lower colours and I'm not convinced they make a stone look whiter in indoor lighting conditions.

Back on the hunt!

 

[sledge]

As a consumer who bought his wife a MB stone, I can say my opinion has changed as I've learned more.

My current thoughts seem to be the only thing that is really predictable is the buyer should receive a price discount of some magnitude for medium+ levels of fluor.

I also think it's a mistake to think or even expect a color boost of any significance as a result of fluor. If you want a G, pony up the bucks because an H with SB isn't the same.

Until vetted and proven otherwise, always assume there is a possibility of a hazy/milky stone when medium+ is present. This probably can't be stressed enough, along with the fact who does the vetting and their invested interest in the results play together mixed with their reputation. In other words, do your homework and be 100% there aren't transparency issues before buying.

Most likely, some of the "science" may seem to disagree because two stones are never truly 100% identical. Not all fluor is blue and not all undertones are yellow (not talking fancies necessarily). Then there is intensity levels. And probably to some degree how the unique set of inclusions of one stone play better or worse than a similar stone with different inclusions.

In short, it's a strong maybe when we talk fluor. Some situations make sense, others don't. Today I'm of the mindset that I'd prefer a stone with none/negligible but if things check out and with the right price discount I may consider a stone with higher levels. When I have better info this may change tomorrow.

For the people buying, they have to make a decision based on the best info they have available to them at the particular time in space. So consumer education is the key. A person needs to be responsible for their own purchase decision but I hope through this forum we can educate and advise people in an accurate and fair manner, even if the specifics change as we learn more.

 

[Starfacet]

I believe that we all agree that any informed diamond seller, gemologist, appraiser, etc should never make a blanket statement about fluorescence being "good" or "bad".

Unfortunately, there are many diamond vendors who preach that fluoro is bad, period. I was in my local jeweler's the other day and the owner was showing a young couple diamonds and telling them that they always want to avoid fluoro because it's bad. I didn't get to talk to my jeweler that day, but on a later visit, I showed her my Elyque oval which is G color with medium blue fluoro. I told her that in direct sun, it has the most gorgeous icy color. She seemed surprised, maybe that I even bought a diamond with fluoro.

So, yes, vendors should be educating people about fluoro instead of telling people to reject those stones out-of-hand. But along with the notion that the only acceptable colors are D-F (Harry Winston) or D-I (Tiffany), the prevailing "wisdom" that diamonds with fluoro should always be rejected will be a tough habit to break.

Also, fluoro is best seen in direct sun, but I don't see many retailers taking their customers out in the sun to look at stones.

 

[Rockdiamond]

Great discussion.
To clarify- I’m not saying that color improvement due to fluorescence is a guarantee. I’m fact it’s quite rare.
More rare, in my experience, than fluorescence that damages a diamonds desirability.

Part of what many of us love about diamonds is the remarkable diversity which is possible. It’s an amazing mineral.
The entire debate about how to excite fluorescence highlights just how little we know about this remarkable characteristic.

Still asking those
who claim that such a study exists to show it to us.

If there was indeed a specific study of this aspect, using scientific methodology, they’d need to study many thousands of diamonds.

Many decades ago you couldn't give these stones away

Hi Arkieb ....Actually my experience in the '70's and '80's was that certain high color fluorescent stones were indeed traded at a premium. At Harry Winston stones like this were called “Premier”

 

[Rockdiamond]

It is well established here that you feel that you have personally seen 'countless' diamonds that look whiter than their color grade in normal lighting due to fluorescence. That is one data point for people to consider.

They may also consider how much credence to put into that statement given what we know scientifically about the conditions under which fluorescence is activated in a diamond. And, for that matter, what GIA says about it based on their surveys.

Hi Bryan,
As I mentioned above, although color improvement due to fluorescence exists, it is indeed rare.
If I used the term "countless" it was a poor choice of words.....although, after all these years as a grader, the actual number of stones I've graded is.....countless

Another "data point" for readers to consider is how much credence to put into "scientific proof" when those claiming there is scientific proof of something refuse to provide the specifics to allow such proof to be examined, or discussed.

 

[Texas Leaguer]

@Rockdiamond ,

As you well know from having been an active participant in many discussions on this topic, there is plenty of science discussed and referenced in various fluorescence threads on this forum -some are linked in this thread. I am not sure what your goal is here, but anyone truly interested can easily avail themselves to those discussions and to that information.

Anyone who does review these threads will also see that you are doing the same thing here that you have consistently done for years- routinely rejecting scientific explanations in favor of your own personal opinions, while apparently expecting that to be edifying to others.

It’s tiresome David. I know how status quo oriented the jewelry industry is, but remember – we all have free will and it’s never too late to evolve.

Also, I would rather drink a beer with you and talk about music than continue beating my head against the wall with you on this topic.

 

[Rockdiamond]

Bryan it would be so very simple if you didn't insist on casting my experience, and that of Gary and others aside as .... "personal opinions" which sounds quite pejorative compared to what you are calling "scientific proof".
I'm anything but "status quo" in this business.....that sort of thing never interested me.......

And you claim I'm aware of all this "scientific proof" but I'm not- and maybe readers also aren't.
There was never a conclusion to Michael's thread. I feel his article was debunked.
Or the GIA study, which is also inconclusive.
If there has been methodical, scientific study, conclusively stating that what I ( and many others) have seen on many occasions wasn't what I saw, I'll reconsider.

Still open to a beer and arguing over whos better, Clapton or Beck.....

 

[Texas Leaguer]

David,
It is not so much a matter of "proof" of any one argument as it is gaining a solid understanding around the topic. From there better insights can be gleaned about the observations being made. It is not my job for instance to "prove" that you are not seeing what you say you are seeing. Furthermore, it is usually futile to try to prove a negative.

We do know from science what causes fluorescence and what conditions are necessary for diamonds to change their visual appearance in response to these emissions.

A light bulb is known to illuminate a room, changing it from dark to bright. But it can only affect that change if it is switched on and there are electrons running through it.

 

[Rockdiamond]

"The results of HRD Antwerp’s study thus support findings from earlier studies conducted by other labs, adding additional objective assessments. It confirms that even very strong fluorescence has no detrimental effect on the appearance of diamonds in a laboratory setting, and when viewed through the pavilion in outdoor conditions, it results in a clear improvement in a diamond’s color. For the wearer or casual observer, fluorescence has a neutral or even positive impact on the appearance of a diamond, making it appear to be more colorless. Given these observations, HRD Antwerp concludes there are no grounds on which to justify the price penalties that currently apply to fluorescent diamonds."

From the last page of Michael's thread. While I feel that the part in red is ill-advised, the bolded portion agrees with what Garry and I ( and others) were saying in that thread.
Bottom line is that there's no scientific, or gemological consensus on fluorescence and color improvement in colorless diamonds.

 

[Rockdiamond]

We do know from science what causes fluorescence and what conditions are necessary for diamonds to change their visual appearance in response to these emissions.

It seems to me that we have not figured out exactly what conditions are necessary- or even what causes different sorts of fluorescence broadly.
It would take the study of many thousands of diamonds to even scratch the surface.

And I will argue Jeff Beck

 

[Rockdiamond]

Unfortunately we now live in a world, well in a country, where enough people poopoo science, education, and even intelligence itself

I think part of the reason we keep getting stuck here relates to this.
I love science and have boundless respect for intelligence and the quest for knowledge.
I too, am distressed by things like how many people belong to the "Flat Earth Society"
Sadly, there's far more serious denial of science going on today.
Thankfully, this subject is nowhere near as serious as that.
But even if we were considering the really serious issues of the day....advancing scientific knowledge must involve questioning what we know, or think we know.
That's not denial, it's advancing understanding through inquisition.
Unfortunately, it's a fine line and quite easy to mistake the two.
I’m not denying science I’d like to explore it in greater depth.

Clearly, there’s some dispute over critical aspects of how fluorescence affects diamonds and when.

We know that sunlight contains a lot of UV.
We know that fluorescent stones light up in the dark under a UV lamp.
We can take meters to check UV levels in different environments.
Yet certain stones behave in unique ways- maybe there's a different spectrum of UV we can't quantify. Maybe these diamonds are different at the molecular level in ways we don't yet understand.

I started this thread- my goal here, as Bryan asked- to spur discussion about fluorescence.
I was motivated by a recent thread asking about a specific diamond, so we really couldn't discuss it openly there.

 

[AV_]

I thought this therad were about 'Flawless' (Fl.) judging by the title, so I opened it thinking about taste & how one type of extraordinary imparts grace; since so any diamonds are runts, let them be perfect in some way or other (FL 'Dark Gray' come to mind - how many can there be!; D FL is the least tricky with no stunts to accomodate into the fundamental diamond lattice; fluorescence is subtle fun - talks if asked the right way & no more).

 

[AV_]

If haziness is present in lighting with insufficient UV intensity to stimulate fluorescence, then the fluoro is not the culprit.

I remember reading a couple of GIA reports on fluorescence & haze, neither of which made it clear that diamonds with fine transparency (by whatever technical threshold) were chosen to evaluate the - separate - effect of fluorescence.

If some level of fluorescence is NOT independent of texture - so there is substantially more likely to have less transparency given enough fluorescence, there is nothing formal published on such relatioship.

@Rockdiamond , I find it intriguing that the folks whoo see most diamonds cannot agree how to excite fluorescence; there is no grand survey out there after all nearly on par with experience to tell of possible types of fluorescence, & surprises come out of the ground (OK, the cooking does do news too - despite all.) Frankly, this is where my recoil at synthetics comes from, leaving alone their properties as assets & all that (recalling a recent post by @Wink on them.)

rambling


___

edited to add

The common description of unhappy fluorescence as 'oily' makes me think twice - almost none looks like that to me; strongly zoned fluorescence might & this tells more about the texture of those stones as well, a type of diamonds to narrow down.

 

[Rockdiamond]

I find it intriguing that the folks whoo see most diamonds cannot agree how to excite fluorescence;

One of the amazing aspects of Pricescope for me is the diversity of opinions among trade members.
For example-Bryan and I grew up in totally different neighborhoods within the diamond business. We have different interests and areas of expertise- we look at different sorts of diamonds.
If we had a brand that excluded Fluorescence, I'm sure I'd look at less fluorescent diamonds.
I see nothing wrong with excluding Fl stones from a brand to ensure consistency.
But it also seems smart to have a separate line of MB/SB stones, based on how many people love fluorescent diamonds.

Among my buddies within the NY diamond scene, the effect is well known.
As I've written many times, some of those buddies who worked with me at Winston worked with "Premier" diamonds- high colors ( D-E-F) with medium or strong blue. We used to really get excited when we saw one. The effects were visible indoors. The grading school at Winston had no windows. I'm not making this stuff up.
Here on 47th street, I've never heard anyone question the fact that some J colors with MB look better than other inert J colors, for that reason alone.

 

[AV_]

to have a separate line of MB/SB stones, based on how many people love fluorescent diamonds.

I see discounts that invite trying the goods & this can only go one way - blue is beautiful.

(D-E-F) with medium or strong blue. We used to really get excited when we saw one. The effects were visible indoors. ... I'm not making this stuff up.

I haven't seen nearly enough. Who does!
(what a photography project this is - to think about, then some serious gear called for)

 

[Rockdiamond]

Prices- dependant on fluorescence
Here's an informal look using the wholesale database, where you can search by fluorescence....

I used a narrow size- a bit over 1ct.
I compared pricing for triple EX G/VS2 no blue, and med blue
Then the same for J, and K

G color- for every dollar you spend on an inert stone, you'd spend .58cents on an MB (MB- 42%)
J color- for every dollar you'd spend on an inert stone, you'd spend .82cents on an MB (MB -18%)
K Color- for every dollar you'd spend on an inert stone $1.09 on an MB......(MB +9%)\
This small sample shows a larger discount on higher colors, smaller discount on J, and actually a premium for K color SB

This tells us little about science- but looking at prices seems an indication of what sells.

 

[sledge]

That shows a very limited time snap of data and doesn't define market trends IMO.

Helping people find stones over the past year or two would contradict your findings. I've not saw 42% discounts on G stones with medium+ levels of fluor. Nor have I saw K's with fluor trade for premiums.

At least when fluor was the only differing characteristic.

If I were trying to predict market trends off your data set I'd want to know how many stones of each color and condition popped up. What range/variance of discount was spread amongst each group. What the max and min discounts were. The average with those max and min outliers and also without the outliers. And finally how many (%) of the available stones are available for a discount such as 42%.

I'd also want to expand my data set to include a minimum one year to show if trends fluctuated by month, and most likely several years to see if there are repeatable occurrences.

 

[Rockdiamond]

All excellent points @sledge.
To perform a complete survey we need far more data.
I picked a single weight to purposely get a narrow snapshot of a very popular category.
A more broad based look would be enlightening.
I don’t believe we can do a “look back”. But I can sample a far broader spectrum.
Also find a better numerical methodology to assess the price differential. It’s possible the manner which I transposed the price differences off the list translates differently to prices at retail.

My goal was a limited look to see if it jibes with what I see in the market.
My experience is that the discounts for MB/SB on G+ colors is substantial compared to inert.
The discounts are smaller for I-J colors and I have indeed seen cases higher prices for certain MB stones in the KLM range as compared to inert.
I’ve also noticed that SI2 stones, in general, are much more difficult to sell- hence far greater discounts compared to VS stones.
Both of these differences have increased over the past five years based on stones I see.

I believe the internet diamond virtual database has exacerbated the differences.

 

[AV_]

Look at D/E for some highly comical discounts! One of those times, methinks.