Weird Fluorescence

[elle_chris]

So yesterday at the appraisers office we were discussing GIA''s medium blue on my new stone.
He put it in one of those black light machine thingies and we hardly saw anything. He couldn''t understand why it said "medium blue" on the report. It was faint at best.
Then he turned it over, pavilion side up.. wow, all of a sudden we saw the "medium blue". This was very strange as I thought if it''s blue, it should be blue all over but it wasn''t. Top up you could barely see it, bottom up it was apparant.

Has anyone seen this type of thing before?

 

[ButterBean]

No I haven''t. But I can''t wait to hear what the cause is! From the table side, do you see any cloudiness at all?

 

[elle_chris]

Date: 2/27/2008 7:53:06 AM
Author: ButterBean
No I haven''t. But I can''t wait to hear what the cause is! From the table side, do you see any cloudiness at all?

Nope none. David Wolf, my appraiser said it''s very uncommon to see the cloudiness even in strong blue fluoro.

 

[Ellen]

I''d like to know too. Hopefully one of the experts will chime in soon.

 

[elle_chris]

well if no experts respond (hoping they do though), i''ll assume it happens from time to time..

 

[diagem]

Its usually like that..., depending on the intensity of the fluo.

Its almost like you grade for color..., the fashion for color grading is table down! You can see the true body color...., in the face up position..., the body color mixes with the reflective light return of the Diamond! Thats why you have sometimes Diamonds graded J but face up looking like an H!

Hope this helps...

 

[elle_chris]

Date: 2/27/2008 11:17:08 AM
Author: DiaGem
Its usually like that..., depending on the intensity of the fluo.

Its almost like you grade for color..., the fashion for color grading is table down! You can see the true body color...., in the face up position..., the body color mixes with the reflective light return of the Diamond! Thats why you have sometimes Diamonds graded J but face up looking like an H!

Hope this helps...

So fluoro is graded face down, and even if it received a medium blue- face up, under the same black light, i won''t see it?
Thank you for responding by the way.

 

[CaptAubrey]

I have seen diamonds with zoned fluorescence, but in general DG is correct--the apparent intensity can vary depending on the faceting style and viewing angle. However, this:

Date: 2/27/2008 11:28:19 AM
Author: elle_chris

So fluoro is graded face down, and even if it received a medium blue- face up, under the same black light, i won''t see it?

is not quite correct. Plenty of medium stones will show medium fluorescence face up. It depends on the diamond.

 

[elle_chris]

thanks for replying.

Hmm.. you''re saying that''s fluoro can be zoned in a stone.. didn''t know that. so while it''s apparant on certain parts of the diamond, i may never see it face up even if it is medium blue.

This is very interesting to me as i''ve never heard or seen it until yesterday.

 

[CaptAubrey]

Date: 2/27/2008 12:14:59 PM
Author: elle_chris
thanks for replying.


Hmm.. you''re saying that''s fluoro can be zoned in a stone.. didn''t know that. so while it''s apparant on certain parts of the diamond, i may never see it face up even if it is medium blue.


This is very interesting to me as i''ve never heard or seen it until yesterday.

Yes, fluorescence can be zoned. It''s caused by chemical impurities in the diamond, and obviously the chemical content of a diamond can vary from one spot to another.

It''s not common, though.

 

[elle_chris]

Thank you for responding yet again!!

I''m picking up the stone tomorrow and getting a black light. Will take pictures of it face up (where you can''t see the fluoro), and face down where it becomes obvious. I thought it was a very strange phenomena. Mr. Wolf also found it uncommon but didn''t elaborate.

 

[CaptAubrey]

Date: 2/27/2008 12:31:03 PM
Author: elle_chris
Thank you for responding yet again!!


I''m picking up the stone tomorrow and getting a black light. Will take pictures of it face up (where you can''t see the fluoro), and face down where it becomes obvious. I thought it was a very strange phenomena. Mr. Wolf also found it uncommon but didn''t elaborate.

Make sure you get a true UV light and not just a regular light bulb with a purple coating. There are inexpensive UV LED flashlights available that will give you a much better idea of what you''ve got than one of those cheap disco lights.

 

[diagem]

Date: 2/27/2008 12:00:56 PM
Author: CaptAubrey
I have seen diamonds with zoned fluorescence, but in general DG is correct--the apparent intensity can vary depending on the faceting style and viewing angle. However, this:

Date: 2/27/2008 11:28:19 AM
Author: elle_chris

So fluoro is graded face down, and even if it received a medium blue- face up, under the same black light, i won''t see it?

is not quite correct. Plenty of medium stones will show medium fluorescence face up. It depends on the diamond.

And depending on the apparatus used....

There are ones with light coming from the top..., some with bottom lights, some higher and lower voltage etc, etc...

 

[Ellen]

Date: 2/27/2008 11:17:08 AM
Author: DiaGem
Its usually like that..., depending on the intensity of the fluo.

Its almost like you grade for color..., the fashion for color grading is table down! You can see the true body color...., in the face up position..., the body color mixes with the reflective light return of the Diamond! Thats why you have sometimes Diamonds graded J but face up looking like an H!

Hope this helps...

Interesting. I wondered if that might not be a reason. Thanks!