Should we discourage or recommend FL stones?

[Texas Leaguer]

What is a ballpark figure of more expensive?

How often would the bulbs need replaced and on how many light boxes?

Given the number of reports done in a year, you'd think $5 more each report would cover the costs, if even that much.

I could see it being more of a pain for the independent jeweler that doesn't make profit from grading reports.

@sledge,
To clarify, my comment was not specific to lab grading. It was about the likelihood that in the future LED lights that illuminate our indoor environments will be completely devoid of UV.

 

[glitterata]

Apologies for interrupting your argument, but now that all you professionals who are passionate about fluorescence are gathered together, I have a question. Does anyone know when technology first existed for observing fluorescence? I mean, obviously sunlight excites fluorescent stones. But it‘s so bright that it also tends to overwhelm the fluorescent effect, making it less noticeable. When did people develop the ability to observe fluorescent objects in a room not illuminated by sunlight? Would Victorians have known their diamonds had fluorescence? Edwardians?

 

[OoohShiny]

Apologies for interrupting your argument, but now that all you professionals who are passionate about fluorescence are gathered together, I have a question. Does anyone know when technology first existed for observing fluorescence? I mean, obviously sunlight excites fluorescent stones. But it‘s so bright that it also tends to overwhelm the fluorescent effect, making it less noticeable. When did people develop the ability to observe fluorescent objects in a room not illuminated by sunlight? Would Victorians have known their diamonds had fluorescence? Edwardians?

I'm not a professional but I am guessing that fluor would not have been detected indoors and out of sunlight (direct or indirect) before electric lighting was invented - I'm assuming that gas lighting and flame-/combustion-based lighting methods have either zero or very little UV content, due to the fact that UV is a high-energy part of the spectrum and, presumably, a lot of energy is lost to heat in any combustion process.

 

[Garry H (Cut Nut)]

Apologies for interrupting your argument, but now that all you professionals who are passionate about fluorescence are gathered together, I have a question. Does anyone know when technology first existed for observing fluorescence? I mean, obviously sunlight excites fluorescent stones. But it‘s so bright that it also tends to overwhelm the fluorescent effect, making it less noticeable. When did people develop the ability to observe fluorescent objects in a room not illuminated by sunlight? Would Victorians have known their diamonds had fluorescence? Edwardians?

Any light that enables you to see violet colored things will provide some excitation.
But gemologically speaking, I expect it was not until the first mercury vapour ordinary fluorescent tubes and in particlual the black UV lights made it possible. Howvere we are still using those available frequencies 100 years later - because they were initially used to ID natural from synthetic rubies and sapphires. That is wrong because the frequencies that excite the strongest blue in diamonds are in the visible and near visible range.

 

[Garry H (Cut Nut)]

Garry.
White leds are not using white emitters as they do not exist.
The are either rgb or phosphor based.
Modern phospher based leds emitters are blue which creates spikes of blue wavelenth light.

http://www.photonstartechnology.com/learn/how_leds_produce_white_light

Karl I was light shopping yesterday and noticed downlights with a switch on the back for 3000k 4000k and 5000k (or there abouts) on LED lamps - I guess they are RGB types?

 

[Karl_K]

Karl I was light shopping yesterday and noticed downlights with a switch on the back for 3000k 4000k and 5000k (or there abouts) on LED lamps - I guess they are RGB types?

yes most likely if it actually changes.
There is a lot of shady stuff out there.

 

[glitterata]

So when (like, what decade) did fluorescence enter the diamond conversation?

 

[Texas Leaguer]

So when (like, what decade) did fluorescence enter the diamond conversation?

From a quick web search:
Both Thomas Edison and Nikola Tesla experimented with fluorescent lamps in the 1890s, but neither ever commercially produced them. Instead, it was Peter Cooper Hewitt's breakthrough in the early 1900s that became one of the precursors to the fluorescent lamp

Looks like fluorescent light overtook incandescent starting in the 1950s

The History of the Light Bulb

From incandescent bulbs to fluorescents to LEDs, we're exploring the long history of the light bulb.

www.energy.gov

 

[Karl_K]

So when (like, what decade) did fluorescence enter the diamond conversation?

Diamonds changing color in sunlight being discussed dates at least back to the 1600s India

 

[glitterata]

Thanks--and when did people who grade and sell diamonds, in particular, become interested in diamonds' fluorescence?

I'm asking partly because I've noticed that my antiques with melee often have a few fluorescent stones, whereas in the few high-end new(ish) pieces I have the melee doesn't fluoresce--which suggests to me that the newer fancy jewelers checked for fluorescence and excluded it, while the earlier ones didn't. (Or it could just be coincidence. It's a very small sample size.)

 

[Texas Leaguer]

Some high end jewelers do sort out the fluoro melee, but generally jewelers do not. Thus, you will see many pieces even today with some fluoro stones in them.

 

[Karl_K]

Thanks--and when did people who grade and sell diamonds, in particular, become interested in diamonds' fluorescence?

I'm asking partly because I've noticed that my antiques with melee often have a few fluorescent stones, whereas in the few high-end new(ish) pieces I have the melee doesn't fluoresce--which suggests to me that the newer fancy jewelers checked for fluorescence and excluded it, while the earlier ones didn't. (Or it could just be coincidence. It's a very small sample size.)

It wasnt considered bad and at times was in demand until the blue-white scandal of the 70s.

Blue White Diamonds - Secrets of the Gem Trade

Introduction and Overview: Blue White Diamonds “…the never failing test for correctly ascertaining the water is afforded by taking the stone under a leafy tree and in the green shadow one can easily detect if it is blue.” Jean-Baptiste Tavernier, 1689 Historically the finest colorless diamonds...

secretsofthegemtrade.com

 

[Texas Leaguer]

@glitterata ,
I think you would really enjoy reading The French Blue by Richard Wise. You can find info about it at the link that Karl posted above.

It's an historical novel based on the voyages of Jean Baptiste Tavenier in the 1600s. Really a fun and interesting read.

 

[Garry H (Cut Nut)]

Aside from this discussion, here is a diamond with a small squarish blue fluoro spot.
It is not an inclusion as there is a feather that is not fluorescing.
This is upside down - very hard to get a good face up photo and I am time poor.

 

[Texas Leaguer]

Aside from this discussion, here is a diamond with a small squarish blue fluoro spot.
It is not an inclusion as there is a feather that is not fluorescing.
This is upside down - very hard to get a good face up photo and I am time poor.

Interesting example of localized fluoro. I bet that one was a head scratcher for the graders! Looks like strong fluoro, but only in a very small portion of the stone. They don't have masters for that!

How was that one reported out Garry?

 

[Garry H (Cut Nut)]

Interesting example of localized fluoro. I bet that one was a head scratcher for the graders! Looks like strong fluoro, but only in a very small portion of the stone. They don't have masters for that!

How was that one reported out Garry?

Faint

 

[John P]

@glitterata ,
I think you would really enjoy reading The French Blue by Richard Wise. You can find info about it at the link that Karl posted above.

I second this for any enthusiast. In addition to Karl's link, some handsome young chap did a teaser and posted purchase info when it debuted.

https://www.pricescope.com/articles/_french_blue_richard_w_wise_gg

I see it's available on Kindle at only $9.99.

 

[Garry H (Cut Nut)]

Bryan and me were arguing in another thread - so bough it here:
edited to add text that did not save at the bottom

Bryan wrote:
GIA Study 1997

It is apparent that the Average Observers were not able to consistently discriminate any fluorescence-related effects in the viewing environments most similar to those in which jewelry is purchased and worn.
Well we must wonder why there is any issue at all if that were true Bryan

GIA Study 2013
Observation of fluorescence can be affected by three main factors: (1) the nature of the emission from the UV light source; (2) the nature of the defect(s) responsible for the fluorescence; and (3) methodology, including the viewing geometry and the distance from the radiation source.

Finally, the distance between the radiation source and the diamond as well as the stone’s orientation (table-down versus face-up) may produce noticeably different fluorescence by changing the amount of excitation energy that interacts with the diamond.

Added text: Can you tell the difference between a D and H in a dim restaurant Bryan? No. But take a blue fluorescent H into much better indoor light and it will improve. Take it outside and in shaded daylight and it will be much better color - and not just for free - but for an unrealistic saving.
This is why Rapaport has changed his position and is saying fluorescence is discounted way to much and even questioning why it is discounted at all. Have you read the article yet?

 

[the_mother_thing]

Pardon the interruption, but might someone have a link to the thread someone started awhile back (e.g., in the last year) re: diamonds with yellow fluorescence or recall who started it? I can’t locate it via Google search, and want to revisit/re-read it, as I stumbled upon two diamonds in my collection that fluoresce yellow. Thanks in advance!

 

[Rockdiamond]

Cool chart Garry!
I had a dealer come by with a cool pair of greenish diamonds the other day.
One had yellow fluorescence- and the other had Green fl.

MOT- yellow fl is much rarer than blue- I'm sure you realize that.
Interesting that I find yellow fl in some colored diamonds seem to have the same effect that blue does in certain colorless diamonds.
In the case of yellow diamonds, yellow fl can increase color ( but not always).
I've not noticed yellow fl impact a colorless stone in indirect sun. But then again, there's so few that it's harder to make generalizations.

The two stones in the video definitely showed effects of fluorescence in indirect sun

 

[Garry H (Cut Nut)]

Cool chart Garry!
I had a dealer come by with a cool pair of greenish diamonds the other day.
One had yellow fluorescence- and the other had Green fl.

MOT- yellow fl is much rarer than blue- I'm sure you realize that.
Interesting that I find yellow fl in some colored diamonds seem to have the same effect that blue does in certain colorless diamonds.
In the case of yellow diamonds, yellow fl can increase color ( but not always).
I've not noticed yellow fl impact a colorless stone in indirect sun. But then again, there's so few that it's harder to make generalizations.

The two stones in the video definitely showed effects of fluorescence in indirect sun

Yes - they are fun effects and can be amazingly addidtive.
Sergey and Janak once polished a diamond (at LTM) that was considered low value and got vivid green (as I recollect) because they managed its very strong green fluorescence.
For the record at the time I believe GIA were using the Judge light box which has some but not a lot of UV.

 

[OoohShiny]

Cool chart Garry!
I had a dealer come by with a cool pair of greenish diamonds the other day.
One had yellow fluorescence- and the other had Green fl.

MOT- yellow fl is much rarer than blue- I'm sure you realize that.
Interesting that I find yellow fl in some colored diamonds seem to have the same effect that blue does in certain colorless diamonds.
In the case of yellow diamonds, yellow fl can increase color ( but not always).
I've not noticed yellow fl impact a colorless stone in indirect sun. But then again, there's so few that it's harder to make generalizations.

The two stones in the video definitely showed effects of fluorescence in indirect sun

I want that fluor!! lol

It is annoying that the stone listings only ever list fluor in terms of absence of strength - I want to be able to search by colour, dammit, as it would be super-cool to have a collection with different fluor

 

[Garry H (Cut Nut)]

I want that fluor!! lol

It is annoying that the stone listings only ever list fluor in terms of absence of strength - I want to be able to search by colour, dammit, as it would be super-cool to have a collection with different fluor

Not true

 

[OoohShiny]

Not true

Ah, my apologies - I should have said the PS Search Engine and listings in the individual websites! (Are they listed on Rap or similar with colour of fluor??)