What causes 'haziness' in some stones w/ fluor?

[yssie]

This is the GIA paper quote: Tradespeople further observed that some gem diamonds with a hazy appearance also fluoresced strong blue to UV radiation. (Paper here)


The paper is careful not to assign causation - or even definitive correlation - to strong blue fluor and the haziness/oiliness often associated as a potential problem with stones w/ strong fluor.

So - if there is a causal relationship here as is commonly suggested here on PS and in conversations with jewellers, if strong blue fluor is responsible for the haziness/oiliness, can one of our tradespeople or experts help me understand why? What property(s) of the emissions/the nitrogen substitutions are to blame?

Or is it just a happenstance characteristic of a diamond that has certain other properties?


I'd really appreciate anyone pointing me in the right direction on this.



ETA: Posted in RT b/c it's a question I think many buyers may have when warned of the possibility of problems with stones w/ strong blue fluor

 

[morse]

Would be interested to know as well.

 

[Circe]

Ditto! In my case, it's because I'd love to find one of these stones ....

 

[CamoKitty]

I'm not sure about the composition that would cause haziness...but I know it's not a guarantee. Brian Gavin has a line of diamonds that are cut to his exacting standards which have medium to strong blue fluorescence. http://www.briangavindiamonds.com/diamond/brian-gavins-blue-diamonds-with-fluorescence/ As far as I can tell, none of them are cloudy or milky. But I am curious to know the answers to your questions as well!

 

[Luv4ever]

This may raise more questions than provide answers.....but when discussing this with Brian Gavin (since I purchased a Brian Gavin Blue from him). He hinted that sometimes Cloud type inclusions can cause this. I did not go into specifics with him. He did say however that he personally inspects all his BGB stones to ensure they don't have that characteristic.

 

[ValentinesJewelryDesign]

GIA has done studies on this and they have concluded that rarely is an oily or cloudy appearance attributable to fluorescence that is "strong" or lower. They noticed an increase in this phenomena mostly in stones with a fluor grade of "very strong". Even with that type of fluor, it was mostly noticeable in the table down position. The industry went a little TOO tight when talking about Fluor and told people to avoid Dias that are strong or higher in Fluor. I DO think that labs have a responsibility to correctly grade diamonds with fluorescence in proper lighting in order to determine body color. THAT should be everyone's main concern. The issue comes that when graded in a fluorescent inducing light, blue fluor can cause a diamond to look much whiter. Obviously this sounds attractive to a consumer, but you need to keep in mind that the diamond will look like it's natural body color when NOT in UV light. In incandescent light it will look more yellow. The oily/cloudy phenomenon should be noted on a grading report as it affects the clarity of the stone....but I wouldn't worry about it if it's not noted. In all, there are plenty of diamonds available with a medium or lower fluor grade. If you don't want to take the chance you definitely don't have to. There IS money to be saved by buying a stone with strong fluor as they tend to be harder to move. I've done this for clients and they've been very happy. As long as they don't look oily or cloudy, the casual observer will never know.


Best regards, Matt

 

[yssie]

Cheers folks.

Just to clarify - this thread is not in any way aimed to question any vendor's goods - I would buy from the BGD Blue line without hesitation, for example. I truly just want to know more about fluorescence and its effects on diamonds - in particular, the question posed. I know what fluor is and why it makes a stone look blue in sunlight, I want to know *if* fluor is directly responsible for the haziness, and if so *why* - or a prod in the right direction, google is being unusually unhelpful!

Luv - re. clouds - and I suppose possibly twinning wisps too - that is interesting! I would feel bad calling in just to pick their brains, since I'm not in the market for a new stone right now I do hope one of our experts will see this thread!

Circe - I think these would be *awesome* in men's jewellery, specifically - ring, cufflinks, earrings, tie-pins... Maybe b/c OldMiner's ring is the first that comes to mind!

Matt - I believe we are referencing the same paper - the quote in bold is from the same.


I found this old thread: [URL='https://www.pricescope.com/community/threads/why-does-it-turn-cloudy.117592/']https://www.pricescope.com/community/threads/why-does-it-turn-cloudy.117592/[/URL] but it doesn't go into detail, unfortunately.

 

[yssie]

..anyone? Pretty please?

Better q, perhaps - is any haziness in the presence of strong fluor actually an effect, or is it something our eyes misread as an effect?

Also asking mods to move this to research.

 

[Garry H (Cut Nut)]

Hi Yssie,
There is a discussion down the second bottom in the Research forum here https://www.pricescope.com/community/threads/how-to-grade-milkyness-in-diamonds.150382/
And I have a journal article somewhere on this subject. (hate the list of contents there)

 

[yssie]

Thanks so much for pointing me to that thread Garry.

I'm understanding from that thread and the others linked that fluor is not thought to cause haziness/oiliness - these stones are already "milky", and some happen to also have fluor. Which answers my questions - and more questions, like insight into how the association began..

 

[Garry H (Cut Nut)]

Thanks so much for pointing me to that thread Garry.

I'm understanding from that thread and the others linked that fluor is not thought to cause haziness/oiliness - these stones are already "milky", and some happen to also have fluor. Which answers my questions - and more questions, like insight into how the association began..

Fluoro is one of some causes, but not all fluoro stones are milky / cloudy.

e.g. One reason I caution people against low clarity eye clean stones is they are often cloudy and suffer a big hit on brilliance.