shape
carat
color
clarity

Fluorescence in D-E-F color Diamonds

Discussion in 'RockyTalky' started by Big Fat Facets, Jul 3, 2019.

  1. Texas Leaguer
    Ideal_Rock
    Trade

    Messages:
    2,921
    Joined:
    Jul 27, 2009
    Big Fat Facets and lovedogs like this.
  2. Texas Leaguer
    Ideal_Rock
    Trade

    Messages:
    2,921
    Joined:
    Jul 27, 2009
    by Texas Leaguer » Jul 6, 2019
    Does anybody know how synthetic diamonds are behaving with respect to fluoro?
     
    Big Fat Facets and lovedogs like this.
  3. Texas Leaguer
    Ideal_Rock
    Trade

    Messages:
    2,921
    Joined:
    Jul 27, 2009
    by Texas Leaguer » Jul 6, 2019
    It wouldn't surprise me if red phospho was indeed that rare.

    This thread gave me an idea. We check fluorescence on thousands of stones every year. But we do not, as a practice, turn off the UV after each check to see if there is any residual phosphorescence. I will start doing so on the diamonds I personally inspect and will suggest it to the other gemologists here.

    Any interesting finds I will report back!
     
    whitewave, TreeScientist, AV_ and 2 others like this.
  4. Demon
    Shiny_Rock

    Messages:
    427
    Joined:
    Feb 16, 2009
    by Demon » Jul 6, 2019
    Yeah, in my dreams lol. I'd prefer a blue, anyway. My J is the only one I have (besides sidetones) that could even be considered white. The red is pretty, though! I have a sapphire that fluoresces red, but it's not the same thing.

    I haven't been able to capture the phosphorescence on camera....not as bright as the fluorescence and my phone just doesn't pick it up. And that's a shame because it really is cool.

    . Fluorescence cropped.jpg Fluorescence cropped2.jpg


    Top picture left to right: chameleon, green yellow with strong blue (doesn't look so strong here, but see it again in the 2nd picture), intense green yellow with strong green.

    Bottom picture (because I didn't get them all in the first): the green yellow again, the intense green yellow again, and the yellow with faint blue.
     
    Last edited: Jul 6, 2019
    AV_ and diamondseeker2006 like this.
    


    


  5. Demon
    Shiny_Rock

    Messages:
    427
    Joined:
    Feb 16, 2009
    by Demon » Jul 6, 2019
    That's a great idea, and I'm kind of surprised it isn't already done. Especially with the colored diamonds.
     
    Big Fat Facets likes this.
  6. OoohShiny
    Ideal_Rock

    Messages:
    5,627
    Joined:
    Apr 25, 2014
    by OoohShiny » Jul 6, 2019
    I thought it was super-cool! :)) When I finally get myself something sparkly (come on, six numbers, that's all I need... lol) I really want it/them to have unusual fluor! A 5- or 7-stone half eternity ring with a range of fluor colours would be awesome :)

    This is a great idea!

    I can't remember - do GIA and/or AGS mention phosphorescence on grading reports?

    Entirely personally speaking, I think it would be ace if vendors included fluor colour in their listings (as well as the HCA tool), perhaps even highlighting unusual colours :)

    There is a link to a paper in a thread by Denver Appraiser in the Lab Grown Diamonds section of the forum, IIRC (am on the phone so it's a faff to search, lol). I think I'm right in saying that MMDs tend to fluoresce orange more often than other colours, but there was a GIA paper I noticed that covered some unusual nickel-based fluor that was green?!

    EDIT: I think this is the thread:
    https://www.pricescope.com/community/threads/gia-on-hpht-synthetics-fall-2017.235388/

    You have a great collection :))
     
    Last edited: Jul 6, 2019
    Big Fat Facets likes this.
  7. Demon
    Shiny_Rock

    Messages:
    427
    Joined:
    Feb 16, 2009
    by Demon » Jul 6, 2019
    I don't have a lot, but I do seem to have more than my share with fluorescence, according to the percentage of diamonds that do so. I actually do have another little white one that doesn't fluoresce, a little olive color and a brown that also don't fluoresce. The only one that I actually looked for fluorescence in was the intense green yellow.
     
  8. Big Fat Facets
    Shiny_Rock

    Messages:
    182
    Joined:
    Jun 7, 2019
    by Big Fat Facets » Jul 6, 2019
    Thank you Bryan!!
     
  9. Big Fat Facets
    Shiny_Rock

    Messages:
    182
    Joined:
    Jun 7, 2019
    by Big Fat Facets » Jul 6, 2019
    well cut oec's are so pretty!! care to share any pictures of your d with strong blue??
     
    AV_ likes this.
  10. Big Fat Facets
    Shiny_Rock

    Messages:
    182
    Joined:
    Jun 7, 2019
    by Big Fat Facets » Jul 6, 2019
    absolutely fascinating!!!
     
    


    


  11. AV_
    Brilliant_Rock

    Messages:
    1,972
    Joined:
    Aug 5, 2018
    by AV_ » Jul 7, 2019
    Do you expect this Rap pricing thing to be around? I see two bets: about the recognition of obvious beauty - where pricing has already given reason for taste to assert itself (idiot discount), and about Rappaport's scoping an inflection in its historical data (price incl.). Is this what you mean?


    I am not finding much technical argument that fluorescence has anything to do with ANY other optical phenomena in diamonds - fog included. It is a hot ticket that it might coincide with any - in whatever rare case (of course this is the sport I love - and if some unusual diamond fits the problem, samples to decide such beautiful questions need to be small (μm) - you are grinding some such off diamonds all the time)


    I had foolishly assumed that checking fluorescence always exposes phosphorescence - else GIA's statement on rarity is Nul, or may stand on other basis than the ad-hoc survey via grading... (that is to say, experimental basis that I do not know of, if within the academic turf of at least one of the GIA directors; if the case can be made that there exists some connection is Br & blue-ness, it would also be not trivial - unless all there is is Hope).

    Digressing, it might be less of a chore to shade the diamonds from UV, on their way out of the action range of the UV source.
     
    Last edited: Jul 7, 2019
    bmfang likes this.
  12. diagem
    Ideal_Rock
    Trade

    Messages:
    4,875
    Joined:
    Oct 21, 2004
    by diagem » Jul 7, 2019
    This is the best question I have seen in a long time...:clap:
    In order for the current changes going through the industry to come full circle, the industry must detox itself from the "man with the papillon" and his decades-old ~ non-transparent price-lists.
    Price lists are so outdated and its time for diamantaires to be able to value their "own" diamonds without the famous Rap sheet on their disposal. I am confident that in five years from now, this will be history as well, there is just no more logic to this anymore. it is kept alive for the addictions of our professionals.

    There is no logic to the fact that diamantaires cannot complete their own inventory counts based on their own real-data calculations.

    But this of course is for another thread...
     
    diamondseeker2006, bmfang and AV_ like this.
  13. AV_
    Brilliant_Rock

    Messages:
    1,972
    Joined:
    Aug 5, 2018
    by AV_ » Jul 7, 2019
    @diagem I have no tenable opinion of The Rap, but might have spent too long thinking of public pricing - in theory and in a few other cases...

    I wonder if & how Rappaport has handled significant price shocks. (Off the cuff: significant change in a category would be met with a reasonably short blackout elsewhere; ergo drop SF, VSF for some time or all time. This line of thinking made me ask @Wink above.)


    _____
    As for the 'investment' matter - I admire the complicated nature of unexpected diamonds & this inclination would make one an appropriate badge.
     
    Last edited: Jul 7, 2019
    bmfang likes this.
  14. Texas Leaguer
    Ideal_Rock
    Trade

    Messages:
    2,921
    Joined:
    Jul 27, 2009
    by Texas Leaguer » Jul 7, 2019
    Inquiring minds want to know more about the green yellow with green fluoro. :read:
    Interesting diamond!
     
    bmfang likes this.
  15. Wink
    Ideal_Rock
    Trade

    Messages:
    7,314
    Joined:
    May 3, 2001
    by Wink » Jul 7, 2019
    You and I have much in common my friend. Sadly, in this case, I fear we are both right, in spite of my hoping that Garry and Yorum are correct. I suggest that you make your bet with Yoram, since I am not wanting to add to my potential gain or loss with Garry.

    Oh, Garry, you suggest that we let our ladies hold the money. I agree. As if they were not already in charge...

    Wink
     
    Last edited: Jul 7, 2019
    AV_, bmfang, OoohShiny and 1 other person like this.
    


    


  16. Wink
    Ideal_Rock
    Trade

    Messages:
    7,314
    Joined:
    May 3, 2001
    by Wink » Jul 7, 2019
    Okay, officially I am betting in US dollars. I suspect that Garry is too. And I know he is very close to the diamond world at a much deeper layer than I am, so he may well have a chance to win.

    So, if I follow your logic, I should have been making this bet once a year for the past 39 years. If I had found someone to disagree with me that fluorescence will be sold at a discount in five years I would now have collected 34 times. Too bad there was no internet, as we know it today, in 1980. And of course, there was no Pricescope back then.

    Wink
     
    AV_, bmfang and lovedogs like this.
  17. Demon
    Shiny_Rock

    Messages:
    427
    Joined:
    Feb 16, 2009
    by Demon » Jul 7, 2019
    It is a .44 Fancy Intense Green Yellow with strong green fluorescence. Cut a little deeper than I'd like for light return, but the color is everything. Vendor photo, then a couple in the sun..... even in the shade, it kind of glows. 148198-oval-fancy_intense-vs2-yellow-b71e9(2).jpg sun1.jpg green sun.jpg
     
  18. lovedogs
    Ideal_Rock

    Messages:
    8,443
    Joined:
    Jul 31, 2014
    by lovedogs » Jul 7, 2019
    It's gorgeous!
     
  19. Demon
    Shiny_Rock

    Messages:
    427
    Joined:
    Feb 16, 2009
    by Demon » Jul 7, 2019
    Thanks. :) I'm still amazed by it a year later, partly because it kind of changes between more green and more yellow. Under office fluor. lights it's kind of a baby poop green, but looks great under any other lights, lol.
     
    OoohShiny and lovedogs like this.
  20. Dancing Fire
    Super_Ideal_Rock

    Messages:
    29,961
    Joined:
    Apr 3, 2004
    by Dancing Fire » Jul 7, 2019
    I believe everything goes in cycles as I believe YG setting will make a come back. Of course you and Garry knows more about the diamond market than I do. :bigsmile:
     
  21. Garry H (Cut Nut)
    Super_Ideal_Rock
    Trade

    Messages:
    14,538
    Joined:
    Aug 15, 2000
    by Garry H (Cut Nut) » Jul 7, 2019
    Wow, I blink and you guys go and have loads of FUN!
    1. Bryan did you say you are retiring?
    2. the basis of my belief is there is new research and more coming that should largely dispel the gossipy stuff. Probably will take 10 years for the dinosaurs to get it but would be a shame to pass up the fun.
    3. some 5 years back the A$ was worth more than the US$. now we get 0.70 :(
    4. Syn diamonds identification is aided by fluoro - for example when short wave fluoro is stronger than long wave the diamonds is most probably synthetic
     
    OoohShiny and bmfang like this.
  22. Garry H (Cut Nut)
    Super_Ideal_Rock
    Trade

    Messages:
    14,538
    Joined:
    Aug 15, 2000
    by Garry H (Cut Nut) » Jul 7, 2019
    D Flawless and Internally flawless 1.00ct non
    faint is 3% cheaper
    Medium is 15.5% cheaper
    Strong is 31.5% cheaper.
    There were no Very Strongs on RapNet
     
  23. Garry H (Cut Nut)
    Super_Ideal_Rock
    Trade

    Messages:
    14,538
    Joined:
    Aug 15, 2000
    by Garry H (Cut Nut) » Jul 7, 2019
    Here is part of a flow chart on using fluoro to answer your question Bryan.
    I only used part because it is proprietary - Branko and John C's
    upload_2019-7-8_11-27-49.png
     
    AV_ and diamondseeker2006 like this.
  24. Wink
    Ideal_Rock
    Trade

    Messages:
    7,314
    Joined:
    May 3, 2001
    by Wink » Jul 8, 2019
    When I was last in Sidney, in mid 1968 on R&R from Vietnam, I seem to recall that the Australian Dollar was about equal to the US dollar, but a few cents off one way or the other. All I remember for sure was that $300 went a long way for this young Marine. The people there treated me like a king and I have always wanted to visit again some day.

    Some things change, like exchange rates. Some things remain the same, or at least, try to.

    I hope I lose the bet while I am still young enough to enjoy selling fluorescent diamonds again, but I do not expect to lose it.

    Wink
     
    AV_, bmfang and TreeScientist like this.
  25. TreeScientist
    Brilliant_Rock

    Messages:
    1,230
    Joined:
    Jan 16, 2018
    by TreeScientist » Jul 8, 2019
    Really interesting discussion so far. Put me on the side of the bet that doesn't believe fluor will begin selling at a premium again. At least, not for a long time. Anytime a gemologist says "There's a small chance that fluor will impact the transparency of your diamond" the general public hears "Blah blah blah fluor will impact the transparency of your diamond."

    I love the appearance of fluor in melee stones. Gives the piece character, and you'll never see the fluor in a tiny melee stone under natural (sunlight) conditions no matter how astute your eyes. I also love unique (non-blue) fluor colors. Below is a pendant that we recently had made that has one melee diamond at the bottom with medium/strong green fluor. So cool to look at under the black light! I would love to buy a yellow diamond with strong yellow fluor one day. Would probably need to open my pocketbook fairly widely though. :mrgreen:

    IMG_20190531_135554686.jpg
     
    Last edited: Jul 8, 2019
  26. Garry H (Cut Nut)
    Super_Ideal_Rock
    Trade

    Messages:
    14,538
    Joined:
    Aug 15, 2000
    by Garry H (Cut Nut) » Jul 8, 2019
    Yup, I will probably lose the bet, but it will be fun, and it probably means taking some nice people to dinner :bigsmile:
     
    Wanaka, bmfang and TreeScientist like this.
  27. TreeScientist
    Brilliant_Rock

    Messages:
    1,230
    Joined:
    Jan 16, 2018
    by TreeScientist » Jul 8, 2019
    Don't go bringing your rationality into a thread about fluorescence in diamonds. :mrgreen::lol-2:
     
    OoohShiny and bmfang like this.
  28. Texas Leaguer
    Ideal_Rock
    Trade

    Messages:
    2,921
    Joined:
    Jul 27, 2009
    by Texas Leaguer » Jul 8, 2019
    I have long believed, and posted here in discussions about fluorescence, that there should be a way to grade transparency. This would help consumers understand a critical aspect related to light performance that would be relevant not only to fluorescence but to clarity in general. There are a number of transparency reducing characteristics that do not necessarily show in a lab report and are often not obvious to the eye, especially the untrained eye.
     
    Last edited: Jul 8, 2019
    bmfang likes this.
  29. Texas Leaguer
    Ideal_Rock
    Trade

    Messages:
    2,921
    Joined:
    Jul 27, 2009
    by Texas Leaguer » Jul 8, 2019
    Not tomorrow, but in the foreseeable future. My kayak needs me, and there are too many redfish on the Texas Gulf Coast. Someone has to do something about it!
     
    Garry H (Cut Nut) likes this.
  30. whitewave
    Ideal_Rock

    Messages:
    7,682
    Joined:
    Feb 29, 2012
    by whitewave » Jul 8, 2019

    garry, as an aside because you are in Aus... what is the average size engagement diamond sold to young couples? :mrgreen2::mrgreen2: Just wondering because my son has a Australian friend/girlfriend (but she has to go back this week). :tongue: He has to go visit her next.
     

Share This Page