Flourescence?

[DiamondTrader 2]

Insofar as wearable diamonds (e.g., higher-end jewelry), what are your personal thoughts about flourescence? I've read the research reports and it appears that this characteristic is still being hotly debated. Unsure whether it's essentially a fifth legitimate judging criteria or, perhaps, a bit of industry slight of hand to distract from the core elements that distinguish one stone from another.

 

Thoughts?

[davidelevi 598]

Personal thoughts: on some stones it's nice, on some others it works less well. Just like anything...

 

It's neither a "fifth criterion" (or if you want to list it at number 5, then there's a lot more than 5), nor is it anything to do with sleight of hand: http://lgdl.gia.edu/pdfs/W97_fluoresce.pdf

[DiamondTrader 2]

Hi Davide, thanks for such a quick reply. I tried the link but the GIA website automatically points to the main page. Did find a 2013 article on the site.

 

http://lgdl.gia.edu/pdfs/W97_fluoresce.pdf

 

For an engagement ring, should diamond fluourescence be a consideration?

[barry 33]

TOTAL NO FACTOR.

 

As the GIA study indicates, one unfortunate incident succeeded in putting the kibosh on fluorescent diamonds to the great detriment of consumers. Fluorescent diamonds were known as "blue-white" back in the day and commanded price premiums of 10-25% depending on the carat-color-clarity combination and were in high demand.

 

Keep an open mind.

[davidelevi 598]

Here is the right link - GIA has moved the article... http://www.gia.edu/doi/10_5741-GEMS_33_4_244

 

I am a little less radical than Barry... I think it is a factor, but just like anything else it's horses for courses.

 

Faint or medium blue fluorescence: never an issue in any way, unless someone is going to get freaked out by a slight blue glow when going to a disco or a tanning salon (only places I can think of where there is enough UV).

 

Strong or very strong blue: potentially an issue - albeit rarely - because of haziness or oiliness. Some people also don't like the fact that it can be seen as a blue tinge in the stone's colour in natural light and/or because they find the "personality change" to be distracting. I love it precisely because of that. Here's a rather dramatic example with an M-coloured stone.

 

In halogen light (no UV):

 

 

in natural, diffused sunlight (enough UV to eliminate the yellow tinge):

 

 

in full sunlight:

 

 

This is about as extreme as it gets. I like the effect, but not everybody does.

 

Note that the stone remains perfectly transparent even with a lot of UV. Not what is called an "overblue".

Edited September 11, 2013 by davidelevi

[denverappraiser 491]

Insofar as wearable diamonds (e.g., higher-end jewelry), what are your personal thoughts about flourescence? I've read the research reports and it appears that this characteristic is still being hotly debated. Unsure whether it's essentially a fifth legitimate judging criteria or, perhaps, a bit of industry slight of hand to distract from the core elements that distinguish one stone from another.

 

Thoughts?

I'm not so sure how hotly debated it is. Nearly everyone agrees that outside of a very few stones it has no visible effect under normal lighting conditions. It drives down the price a bit, which for most people is a feature not a problem, and it makes resale difficult in the current marketplace. How much of a problem that is depends on your objectives and, of course, current popularity or lack of it doesn't mean it won't be popular in the future. As Barry mentioned, a few decades ago blue/white was seen as a feature and commanded a premium for example.

 

Realistically I think the problem is the Internet search engines, both at the consumer and wholesale levels. If you search for specs on a fairly popular stone, say 1.00 F VS2, you'll find hundreds or even thousands of stones for sale. Which to pick? People want to narrow it down to 1 or maybe 2 and they don't actually have very much data to go by. Lab, price, claims about cutting and location are popular but you're still left with dozens or even hundreds to choose from. Now what? That's when people start using things like the HCA, Brilliancescope, 'minor' attributes like fluoro, the key to symbols, and similar filters. It's less a matter of ending up with what is demonstrably the best as it is limiting the selection down to something manageable.

 

The other Internet effect is the worry about those 'overblues'. A few percent of the stones graded strong blue will show a milky or oily effect in sunlight. For people who are buying sight unseen, this is a great worry. Then they worry about misgraded stones. Sometimes medium means strong after all. Maybe medium is a worry, so it's easiest to just avoid them too. The old time test of simply looking at it in the sunlight is harder to arrange.

Edited September 11, 2013 by denverappraiser

[DiamondTrader 2]

Great info, DenverAppraiser, DavidELevi and Barry. DavidE, your pics really drive the point home.

 

Thanks to each of you!

Edited September 11, 2013 by DiamondTrader

[barry 33]

DT-Most welcome.

 

David; Having gone through the "blue-white" period and seen the happy customer faces with their "blue-white" stones, I would say that the current dismissal/knock of-on fluorescence is a bit to the radical side. Neil makes a good point that with so many diamonds on the market and information, consumers do try to fine tune their search by weeding out any type of information that is "negative" or difficult to get a handle on.

[davidelevi 598]

Barry - entirely agree about the radicalisation of views on fluorescence (and on so many other things from laser drilling to % tables, just to mention the last two that happened on this forum). I also agree with Neil (and you) that the extreme ease of getting hold of some pieces of information (and the relative difficulty of getting hold of others) which characterises the internet era is a root cause of much of this.

 

I'm simply being a bit less categorical than your "TOTAL NO FACTOR" above - fluorescence can have an effect on looks in some circumstances (beyond the "overblown overblue" issue), some people like it some don't. Should it justify the sometimes extreme discounts seen? In no way, but if you like fluorescence, then - to use Neil's expression - it becomes a feature, not a negative. If you don't, then you are better off avoiding it from the start.

[barry 33]

Good points.

[karsa 1]

 

Insofar as wearable diamonds (e.g., higher-end jewelry), what are your personal thoughts about flourescence? I've read the research reports and it appears that this characteristic is still being hotly debated. Unsure whether it's essentially a fifth legitimate judging criteria or, perhaps, a bit of industry slight of hand to distract from the core elements that distinguish one stone from another. Thoughts?

I'm not so sure how hotly debated it is. Nearly everyone agrees that outside of a very few stones it has no visible effect under normal lighting conditions. It drives down the price a bit, which for most people is a feature not a problem, and it makes resale difficult in the current marketplace. How much of a problem that is depends on your objectives and, of course, current popularity or lack of it doesn't mean it won't be popular in the future. As Barry mentioned, a few decades ago blue/white was seen as a feature and commanded a premium for example.Realistically I think the problem is the Internet search engines, both at the consumer and wholesale levels. If you search for specs on a fairly popular stone, say 1.00 F VS2, you'll find hundreds or even thousands of stones for sale. Which to pick? People want to narrow it down to 1 or maybe 2 and they don't actually have very much data to go by. Lab, price, claims about cutting and location are popular but you're still left with dozens or even hundreds to choose from. Now what? That's when people start using things like the HCA, Brilliancescope, 'minor' attributes like fluoro, the key to symbols, and similar filters. It's less a matter of ending up with what is demonstrably the best as it is limiting the selection down to something manageable.The other Internet effect is the worry about those 'overblues'. A few percent of the stones graded strong blue will show a milky or oily effect in sunlight. For people who are buying sight unseen, this is a great worry. Then they worry about misgraded stones. Sometimes medium means strong after all. Maybe medium is a worry, so it's easiest to just avoid them too. The old time test of simply looking at it in the sunlight is harder to arrange.

Perhaps in that case faint flourescence should be no problem then?

Someone on a forum mentioned that people should avoid diamonds with strong flourescence, but faint to medium should be fine.

From my perspective, to be on the safe side especially when buying online, a diamond with faint flourescent characteristic should be okay.

[davidelevi 598]

"safe side" of what? There is nothing inherently unsafe about fluorescence.

[karsa 1]

Here is the right link - GIA has moved the article... http://www.gia.edu/doi/10_5741-GEMS_33_4_244

 

I am a little less radical than Barry... I think it is a factor, but just like anything else it's horses for courses.

 

Faint or medium blue fluorescence: never an issue in any way, unless someone is going to get freaked out by a slight blue glow when going to a disco or a tanning salon (only places I can think of where there is enough UV).

 

Strong or very strong blue: potentially an issue - albeit rarely - because of haziness or oiliness. Some people also don't like the fact that it can be seen as a blue tinge in the stone's colour in natural light and/or because they find the "personality change" to be distracting. I love it precisely because of that. Here's a rather dramatic example with an M-coloured stone.

 

In halogen light (no UV):

 

 

in natural, diffused sunlight (enough UV to eliminate the yellow tinge):

 

 

in full sunlight:

 

 

This is about as extreme as it gets. I like the effect, but not everybody does.

 

Note that the stone remains perfectly transparent even with a lot of UV. Not what is called an "overblue".

If the diamond was for myself, I would definitely prefer a medium flourescent diamond since I like the fact that the diamond glows blue under UV radiation.

[karsa 1]

"safe side" of what? There is nothing inherently unsafe about fluorescence.

Thats true. Flourescence does not bite But it may be an undesirable feature to some individuals that do not like the blue glow under UV light, but as you said, it is a beautiful feature for a diamond to have and i would choose a diamond for myself which has that feature.

 

Also, what color diamonds typically would have this sorta yellow tinge under diffused lighting, and what level of flourescence is optimal to negate the yellow tinge under various types of lighting?

Edited September 11, 2013 by karsa

[davidelevi 598]

The diamond above is an M / Very Strong Blue. And the answer to your second question doesn't really exist - or if you prefer, it's an equation with an infinite number of solutions.

[karsa 1]

The diamond above is an M / Very Strong Blue. And the answer to your second question doesn't really exist - or if you prefer, it's an equation with an infinite number of solutions.

If that is the case, buying a diamond online especially if you cannot see the diamond may not be an easy decision.

 

Also, i believe somebody on this forum was mentioning about how diamonds regardless of color (whether its a D, E, F, G, H etc)

can have a slight brownish tint to it. Does GIA or AGS take into account the 'tint' characteristic when grading a diamond? Or is this something a person would have to verify visually speaking?

Edited September 11, 2013 by karsa

[davidelevi 598]

Yes, both GIA and AGS will tell you if there is a brown tint to the diamond even though it's still going to be graded on the D-Z scale

 

[karsa 1]

Yes, both GIA and AGS will tell you if there is a brown tint to the diamond even though it's still going to be graded on the D-Z scale

 

Thank you! Which means tint should not be a problem for a diamond graded by GIA if it is not listed.

Also transparency should not be an issue as well if the stone is above a VS1?

[davidelevi 598]

Most unlikely to be an issue on VS (1 or 2); however there are cases where internal strain is present even without inclusions. Easily detected with a polariscope, but not information available on a GIA report.

[mellowyellow 17]

I did not know that gia tells you if there is a Brown tint! I thought a tint was a tint and is luck of the draw!

 

Davide can you be really lucky and get an I J or K stone with a pink tint?

Edited September 12, 2013 by mellowyellow

[davidelevi 598]

Anything other than yellow, brown or grey is considered a coloured diamond and ends up on the "colored diamond scale".

 

This is what a report for a pink-tinted stone looks like:

 

 

And here is the stone - the pinkish tone is just about visible here:

 

 

But can be encouraged with a good setting to come out a lot more:

 

Edited September 12, 2013 by davidelevi

[thediamondshopper 9]

Beautiful diamond Davide, the inclusion fit almost perfectly under the claw. Ive was meaning to ask what the colored speckles are on the tweezers and parts of the diamond.

 

Also further on the issue of fluorescence, if going with strong and very strong I tend to prefer AGS over GIA as their grading environment has considerably less UV and thus the color grade would not be influenced as much by the presence of the fluorescence. 

Edited September 12, 2013 by thediamondshopper

[mellowyellow 17]

Darn! So there's no such thing as a free lunch! I had visions of someone sitting on the floor scouring through to find a pink tinted diamond!

 

Davide if it gets on the pink scale does the price sky rocket? The reason I ask is because I see these teeny tiny pink diamonds that cost $30,000 etc!

 

What is a grey hue like? Would you say yellow hue was most desirable? How does a brown hue look? Should I start another thread? Sorry for hijacking! 

Edited September 12, 2013 by mellowyellow

[davidelevi 598]

Anything that contains the words "natural pink diamond" next to each other is expensive... that one above was over $50k for a 1.62 SI1 stone that as a D colour fantastic cut would be less than $20k.

 

However if you really want to see the prices skyrocket, you need to go Fancy Pink and above; there $50k will get you a half carat stone...

 

A grey is... grey. Steely is what comes to mind. Here is a nice Fancy Light Grey. Nice because it's still very transparent and bright; often greys look muddy and opaque.

 

 

And here's a faint brown (in fact, the one whose report I posted above):

 

 

If I had to pick a hue, I'd say that grey is the least visible, yellow is the least bothering (greys tend to be dark and "overcast"), and brown can be the prettiest if it is well exploited - but it's also the one that looks the least "white".

[davidelevi 598]

Beautiful diamond Davide, the inclusion fit almost perfectly under the claw. Ive was meaning to ask what the colored speckles are on the tweezers and parts of the diamond.

 

[snip]

 

I think it's dust... no matter how clean you think a diamond is, putting it in full light and taking a photo seems to generate dust on it.