So about that negligible flouresence
- Thread starter beardog
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Totally. I find it hilarious that these AGL and GIA gemologists still can’t broaden their toolkit to more than just the standard bandwidth for UV. Like, how do you miss this??? Honestly, there is no excuse. I’ve seen too many recent examples of this to trust that particular grading parameter. And it matters because it affects the cost.
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I love fluorescence too. I prefer it. But if it affects pricing, and affects the stone visually in certain types of light, the fact that AGL and GIA are dramatically ignoring part of the spectrum needs clarification by vendors at a minimum.
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I agree... except... since flurescence is viewed as a negative, I would be afraid that if GIA and AGL started listing the entirety of the spectrum Wf and others wouldn’t stock anything that didn’t have “none” listed. It’s a double edge sword, at least for me. Right now I bank on the fact that I may get an AGL that lists “negligible” but get a stone that still has some (which has happened at least 50% of the time for me).
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We have an ACA and I want to see where it falls on the GIA scale if it even has any fluorescence at all...
We love it, so it's not going anywhere. I'm retired with time to waste on mere curiosity.
According to WF, the AGS Negligible is a combination of GIA's None & Faint.
www.whiteflash.com/about-diamonds/diamond-education/diamond-fluorescence-good-or-bad-1322.htm
I've looked at cheap blacklights and don't know which ones are real UV and which ones are some piece of junk bulb putting out some UV and some barely visible blue.
I'd love to have a collection like the one in this video. www.youtube.com/watch?v=v9WnzFAOit0
"natural fluorescent diamonds on display at the Natural History Museum in London"
We love it, so it's not going anywhere. I'm retired with time to waste on mere curiosity.
According to WF, the AGS Negligible is a combination of GIA's None & Faint.
www.whiteflash.com/about-diamonds/diamond-education/diamond-fluorescence-good-or-bad-1322.htm
I've looked at cheap blacklights and don't know which ones are real UV and which ones are some piece of junk bulb putting out some UV and some barely visible blue.
I'd love to have a collection like the one in this video. www.youtube.com/watch?v=v9WnzFAOit0
"natural fluorescent diamonds on display at the Natural History Museum in London"
Not sure the model but it's a Craftsman from Lowe's. Not sure if youre in the States but it's in store for like$10
It's an I, so I honestly view it as an asset, as I see no stand alone tint. Was just suprised
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Wow, that stone throws off more fluor than my BGD Blue stone that has MBF. Not sure the exact UV wavelength of the flashlight you are using. Maybe that is some of the difference? I am using the light that BGD shipped with fiancee's stone.
Speaking of this -- keep in mind, when testing for fluor you need to use the proper UV wavelength. Below is a post I found from diamond wizard, John Pollard.
Also, I would agree with several of you that I am not bothered by fluor itself. However, the fact remains that stones designated as none/faint/negligible trade for a higher value than stones with medium/strong grades.
Personally, it would bother me to learn I paid for a stone with none/faint/negligible fluor and then learn it is popping like a glow stick. Granted, it doesn't change the beauty of the stone and probably not even resell as the cert will still say none/faint/negligible.
As many pics as we see of fluor I found this interesting as it shows UV and normal lighting conditions together.
Speaking of this -- keep in mind, when testing for fluor you need to use the proper UV wavelength. Below is a post I found from diamond wizard, John Pollard.
Also, I would agree with several of you that I am not bothered by fluor itself. However, the fact remains that stones designated as none/faint/negligible trade for a higher value than stones with medium/strong grades.
Personally, it would bother me to learn I paid for a stone with none/faint/negligible fluor and then learn it is popping like a glow stick. Granted, it doesn't change the beauty of the stone and probably not even resell as the cert will still say none/faint/negligible.
As many pics as we see of fluor I found this interesting as it shows UV and normal lighting conditions together.
Re: Wavelength of UV light for viewing fluorescence in diamo
Hello jstarfireb. Congrats on the upgrade - and cool idea.
Good info from WMW and likely exactly what you needed to know. GIA uses both long-wave (@ 365 nm) and short-wave (@ 254 nm) but SW is mainly for lab ID purposes. Of course some specimens like the Hope Diamond do fluoresce and phosphoresce to SW so it's fun to check both aspects with any stone...but you're only looking for LW, I expect.
An appraisal-quality unit will have both (LW 366 nm SW 254 nm). The GIA store sells this for $879.
http://www.eickhorst.com/en/gemmological-instruments/uv-lamps/multispec/features/
I keep one of these Kassoy LWs next to my loupe in my briefcase. It's 380 nm. As WMW implied that will do just fine.
http://www.kassoy.com/9-uv-led-light.html
This may be even more up your daily-use-alley? Inexpensive UV keychain-lights. Listed at 370 nm (but ymmv).
http://www.photonlight.com/categories/LED-Flashlights/By-Brandhoton/?sort=bestselling
I've seen those Photon keychain-lights offered by diamond-tool sellers for a higher markup. When I have seen them used they appear to do well at fluorescence-excitement. For practical applications the $25 Kassoy is profoundly stronger, logically.
Photos next, please.
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