Medium blue fluorescence in Colourless (D-F) Round Brilliant: go for it or stay away

[Sydneyphoenix]

I understand in D-F colourless round brilliant diamonds strong fluorescence makes the diamond look hazy/cloudy and it’s thus an undesirable feature. Whereas such haziness is usually not an issue in stones with no or faint fluorescence. So what about medium (blue) fluorescence, it’s often at a slight discount compared to comparable stones with no fluorescence but is the risk of haziness too great for colourless D-F diamonds and thus not worth the risk? Thinking specifically 1ct round brilliant with F colour, VS2/SI1 clarity (lowest grade possible as long as eye-clean), triple excellent GIA stones.

 

[lulu_ma]

Totally depends on the stone.

Haziness can be an issue regardless of color grade, but there’s only a small chance that the SBF will cause milkiness.

What’s the return policy?

 

[freddyboston]

exactly.. it really depends on the diamond... i have a D Si1 (eye clean) Strong Blue with clarity based on a crystal, a needle and a few pinpoints (no graining / no clouds / no twin wisps) so the FL is only a benefit... bonus was getting a D for an H price

 

[0-0-0]

I only buy natural diamonds with fluorescence. In my experience color has no influence on whether a diamond goes hazy/milky. The only ones I have that go hazy/milky have internal graining and/or strong phosphorescence alongside strong fluorescence.

 

[freddyboston]

my SB has patches of strong white phosphorescence (brief when lights turned off) to no ill effect....

 

[seaurchin]

I love fluorescence. It is so cool. I and am disappointed if a diamond I'm considering doesn't have any.

 

[jjca]

@freddyboston
I love all of your posts and comments.
My original ER was an F with faint blue with a side stone of medium blue. In the 24 years I had it - I never once noticed the fluorescence in either - but boy were they bright, icy white!
I also recently discovered that 1 of the stones in my TAG watch (just one) has strong or medium blue - and I never knew until I recently bought a loupe withe a UV light.
Your passion for fluorescence is inspiring and I always look for your input when a user asks about it. You might be on to something with the authenticity of a natural stone with it - as a way to set it apart from a lab. I also think it's a great way to save some money on a large stone - especially one that is not quite colorless.
Thanks for your posts and input!

 

[Sydneyphoenix]

Totally depends on the stone.

Haziness can be an issue regardless of color grade, but there’s only a small chance that the SBF will cause milkiness.

What’s the return policy?

Good return policy from the vendor I’m looking at, just looking atm, not committed to buying yet.

I love fluorescence. It is so cool. I and am disappointed if a diamond I'm considering doesn't have any.

I only buy natural diamonds with fluorescence. In my experience color has no influence on whether a diamond goes hazy/milky. The only ones I have that go hazy/milky have internal graining and/or strong phosphorescence alongside strong fluorescence.

Where do you draw the line, medium or strong fluorescence? I appreciate you have to look at each diamond individually even if graded as medium or strong fluorescence etc.

 

[lulu_ma]

Can’t draw a line-it really depends on the individual diamond.

 

[0-0-0]

I draw the line based on whether there are clouds, internal graining, and twinning wisps noted on the GIA report. They are more likely to cause the diamond to go hazy/milky alongside fluorescence. IMO medium/strong fluorescence is less of a factor.

 

[Garry H (Cut Nut)]

Good return policy from the vendor I’m looking at, just looking atm, not committed to buying yet.




Where do you draw the line, medium or strong fluorescence? I appreciate you have to look at each diamond individually even if graded as medium or strong fluorescence etc.

You draw the line at Very Strong, as that is super technical to pick a winner.
You also need videos rotating vertically to see if there is internal graining (which GIA miss 80% of the time.
And no clouds.
These two, and really strong Twinning, interact with the fluoro to make the stone hazy.
Otherwise strong blue's have about 5% more brightness and appear much whiter to the human eye.