Strong blue fluorescence in southern vs northern hemisphere skies

[CalliopeCladdagh]

Hi everyone,

Yes - another question about fluorescence! Apologies, I know this subject has been discussed at length but I don't think my question has already been addressed.

Interested in 2 diamonds, one with medium and one with strong blue fluorescence. Both J colour.
I'm not afraid of the fluoro per se, but am curious whether the effect will appear stronger where I live (NZ). We tend to have very blue skies, and have holes in the ozone layer that give us very strong sun. Do you think this will affect it and could it potentially raise the chance that the diamond would appear milky?

The diamonds are in the US so I'm unsure whether photos taken over there will be representative of what I would see here.

With the distance and customs charges etc I really want to avoid having to make a return and if I have doubts I won't purchase - but that would also mean potentially missing out on some good diamonds.

 

[PrismBaby]

I did have a customer years ago from California that came to visit us in NY, she was considering a diamond with strong blue FL and she was fine with how it looked in sunlight here but when she brought it back to CA, it bothered her. It didn't necessarily make the diamond milky but rather glowed too much for her liking.

 

[Garry H (Cut Nut)]

Hi everyone,

Yes - another question about fluorescence! Apologies, I know this subject has been discussed at length but I don't think my question has already been addressed.

Interested in 2 diamonds, one with medium and one with strong blue fluorescence. Both J colour.
I'm not afraid of the fluoro per se, but am curious whether the effect will appear stronger where I live (NZ). We tend to have very blue skies, and have holes in the ozone layer that give us very strong sun. Do you think this will affect it and could it potentially raise the chance that the diamond would appear milky?

The diamonds are in the US so I'm unsure whether photos taken over there will be representative of what I would see here.

With the distance and customs charges etc I really want to avoid having to make a return and if I have doubts I won't purchase - but that would also mean potentially missing out on some good diamonds.

First make sure the diamonds have no internal graining or large clouds (more than 5% of the diamond).
They cause milkyness hazy in medium and strong fluorescent diamonds.
Put a hold on them and link us please.

Re NZ - Ozone layer is way south and only important if the sunlight is coming thru the hole (but the hole has repaired since the world stopped using the refrigerant that caused the problem).

I am in Melbourne, and yes, our smaller populations and southern skies with winds mostly from the south give us clearer skies so there is more UV, but that is mostly more of the shorter wave types which are not the frequencies that cause the blue fluorescence. They just sunburn you faster!

 

[Garry H (Cut Nut)]

The diamonds are in the US so I'm unsure whether photos taken over there will be representative of what I would see here.

Almost all photos and videos are made under LED lighting these days and those have none or very little of the violet and near visible violet that cause blue fluorescence. So they are only of use to check for internal graining (which GIA almost always miss these days).

 

[CalliopeCladdagh]

First make sure the diamonds have no internal graining or large clouds (more than 5% of the diamond).
They cause milkyness hazy in medium and strong fluorescent diamonds.
Put a hold on them and link us please.

Re NZ - Ozone layer is way south and only important if the sunlight is coming thru the hole (but the hole has repaired since the world stopped using the refrigerant that caused the problem).

I am in Melbourne, and yes, our smaller populations and southern skies with winds mostly from the south give us clearer skies so there is more UV, but that is mostly more of the shorter wave types which are not the frequencies that cause the blue fluorescence. They just sunburn you faster!

Thank you - this is exactly the kind of info I was after!

So the strong blue has already gone/sold, but here's the medium:

https://www.bluenile.com/nz/diamond-details/LD21184353

I would welcome any feedback on the cut as well.
They're under a carat so I don't get a clarity plot on the cert which makes me a little nervous.

 

[Garry H (Cut Nut)]

The.stone will fire somewhat like an old cut. The spread is rather small for the weight. About 70 point equivalent in a round.
This is essentially a round cut oval. A traditional oval can have a spread 5 or more % larger than this stone.
But it is an interesting look.

 

[lovedogs]

Thank you - this is exactly the kind of info I was after!

So the strong blue has already gone/sold, but here's the medium:

https://www.bluenile.com/nz/diamond-details/LD21184353

I would welcome any feedback on the cut as well.
They're under a carat so I don't get a clarity plot on the cert which makes me a little nervous.

I love it! It's a nice oval shape but with round h&a design

 

[CalliopeCladdagh]

@Garry H (Cut Nut) resurrecting this to ask you ypur opinion on this diamond please? Specifically do you think it will have a good amount of fire (will it be similar to the 0.9 you commented on for me above)

https://www.bluenile.com/nz/diamond-details/LD21158825

 

[CMN]

First make sure the diamonds have no internal graining or large clouds (more than 5% of the diamond).
They cause milkyness hazy in medium and strong fluorescent diamonds.
Put a hold on them and link us please.

Re NZ - Ozone layer is way south and only important if the sunlight is coming thru the hole (but the hole has repaired since the world stopped using the refrigerant that caused the problem).

I am in Melbourne, and yes, our smaller populations and southern skies with winds mostly from the south give us clearer skies so there is more UV, but that is mostly more of the shorter wave types which are not the frequencies that cause the blue fluorescence. They just sunburn you faster!

What about if a GIA report says “internal graining not shown” for a medium blue fluorescent stone. Is this indicative that the graining is less than a certain %?

 

[Garry H (Cut Nut)]

To avoid hazy milkyness then yes, avoid blue fluorescent diamonds with graining and large clouds.
If GIA notes internal graining - then it is usually very strong as in their lighting set up (assuming they still actually look at diamonds) they would rarely see it under a microscope.
I would want an expert opinion. but it does depend on 2 things.
1. How bad the graining (or clouds) are
2. How strong the fluorescence is.
There are large variations in the grading of fluorescence. GIA has never openly said that it uses 365nm or a longer wavelength in the visible or near visible range 405 to 385nm. I assume they still use 365nm (which is dumb and wrong IMHO) but they have a track record of changing things and not really notifying the world until years later or maybe never (perhaps for competition purposes?).
I just found these two extreme examples of the range that GIA have called medium (and I do not know what UV was used for the photos):