Natural or Synthetic Spinel? Fluorescence?

[_BUQARI_]

Is it possible for a Synthetic Spinel to got any Fluorescence?
If not, do you think this one is Natural?

The clarity is IF-FL.
Carat Weight is 4.02 carat.
No bubbles or inclusions at all, but a very tiny chip at the back.

Fluorescence under UV is Reddish/Purplish/Pinkish.
Hard to catch with the camera.

The color in daylight is approx. 60% Red and 40% Pink.
Red with Pink flashes.

All answers are appreciated!
Thank you!

 

[davi_el_mejor]

Strong/intense red fluorescence in spinel is usually a sign of synthetic spinel. Coupled with the IF/FL clarity, it's very suspect. The best way to know for sure is to find the RI of the stone.

 

[_BUQARI_]

Strong/intense red fluorescence in spinel is usually a sign of synthetic spinel. Coupled with the IF/FL clarity, it's very suspect. The best way to know for sure is to find the RI of the stone.

Thanks for your reply!
The fluorescence is not red, it's more like purple/pink.
But it might happen because the stone is red so the UV mix?

 

[chrono]

Both synthetic and natural Burmese red spinel can have strong fluorescence. The problem here is that you don't have any inclusions that rule out a synthetic. Being able to find a negative crystal will point to it being a natural spinel. Using a good microscope will help in this case. If you can get your hands on one, see if the crystal is single or double refractive. Natural spinels are easy to separate from flame fusion synthetics but more difficult to separate with flux grown synthetics.

 

[chrono]

I took a second look at your pictures and gave it more thought. Are you sure your spinel fluorescences? It doesn't look like it does in any of your pictures. The link below shows a ruby but you can see that it clearly fluorescences or glows. Yours just looks purple as the pink colour is affected by the blue light.
http://www.google.com/imgres?imgurl=http://www.ruby-sapphire.com/images/heat-seeker_uv_fluorescence/ruby_no_green_filter.jpg&imgrefurl=http://www.ruby-sapphire.com/heat_seeker_uv_fluorescence.htm&h=404&w=500&sz=32&tbnid=gQJEjv80DQQ2vM:&tbnh=85&tbnw=105&zoom=1&docid=aMpKboP7aoLK3M&hl=en&sa=X&ei=eG-qT-6UIJKy8ATOzPC8Aw&ved=0CIEBEPUBMAM&dur=0

 

[_BUQARI_]

Both synthetic and natural Burmese red spinel can have strong fluorescence. The problem here is that you don't have any inclusions that rule out a synthetic. Being able to find a negative crystal will point to it being a natural spinel. Using a good microscope will help in this case. If you can get your hands on one, see if the crystal is single or double refractive. Natural spinels are easy to separate from flame fusion synthetics but more difficult to separate with flux grown synthetics.

There's no inclusions at all under 45x loupe in the Spinel pictured, only at little chip at the back (4.02 carat).

I got another Spinel as well that I know for 100% sure that is Natural, and that one is also FL/IF under 45x loupe (4.15 carat).
The 4.15 carat doesn't got any Fluorescence at all.

Yes, I got plenty of Natural Unheated Rubies, and I know the way they use to Fluorescence.
But the 4.02 carat Spinel has more like Red flashes in it - there's no "solid" Fluorescence.
So I dont know if the color is mixing with the UV or not.
When seen under UV-light (SW) it seems to be Pink/Purple.
But when moving the Spinel little around - there's Red flashes in between the Pink/Purple color.

GLASS?
Any idea?
I only ask this question whether to know to spend $450.00 at a AGL Report or not.

 

[LD]

I agree with Chrono - your photos don't look like fluorescence. Here's a photo of one of mine (3rd line down) - Mahenge Spinel with strong fluor.

The lack of inclusions would be more of a worry to me.

 

[_BUQARI_]

I agree with Chrono - your photos don't look like fluorescence. Here's a photo of one of mine (3rd line down) - Mahenge Spinel with strong fluor.

The lack of inclusions would be more of a worry to me.

Thanks for your reply!

Yes, but I have natural Spinels that's FL-IF under 45x as well (without fluorescence).
Only thing I react to is the main color of the one pictured, it's almost too good to be true.
So that's why I start wonder if it's a catch or just a synthetic ...

 

[_BUQARI_]

I agree with Chrono - your photos don't look like fluorescence. Here's a photo of one of mine (3rd line down) - Mahenge Spinel with strong fluor.

The lack of inclusions would be more of a worry to me.

Thanks for your reply!

Yes, but I have natural Spinels that's FL-IF under 45x as well (without fluorescence).
Only thing I react to is the main color of the one pictured, it's almost too good to be true.
So that's why I start wonder if it's a catch or just a synthetic ...

 

[_BUQARI_]

Is it possible for a Synthetic Spinel to got any Fluorescence?
If not, do you think this one is Natural?

The clarity is IF-FL.
Carat Weight is 4.02 carat.
No bubbles or inclusions at all, but a very tiny chip at the back.

Fluorescence under UV is Reddish/Purplish/Pinkish.
Hard to catch with the camera.

The color in daylight is approx. 60% Red and 40% Pink.
Red with Pink flashes.

All answers are appreciated!
Thank you!

Pictures taken in sunlight.

 

[RedSpinel]

Strong/intense red fluorescence in spinel is usually a sign of synthetic spinel. Coupled with the IF/FL clarity, it's very suspect. The best way to know for sure is to find the RI of the stone.

But shouldnt the RI be the same for synthetic spinel as it is for natural spinel since they are chemically and elementarily the same?

To the OP... If its real, its got great color! If its real, its a great stone! Its really not all that uncommon to find clean spinels, especially compared to rubies. If you look enough, and you're in the right price range, you'll find eye-clean spinels....

 

[_BUQARI_]

Strong/intense red fluorescence in spinel is usually a sign of synthetic spinel. Coupled with the IF/FL clarity, it's very suspect. The best way to know for sure is to find the RI of the stone.

But shouldnt the RI be the same for synthetic spinel as it is for natural spinel since they are chemically and elementarily the same?

To the OP... If its real, its got great color! If its real, its a great stone! Its really not all that uncommon to find clean spinels, especially compared to rubies. If you look enough, and you're in the right price range, you'll find eye-clean spinels....

Thank you so much for your input!
I attached a picture of another Spinel I got, 100% Natural (tested), 4.15 carat, FL-IF clarity, no fluorescence.
The difference between the two is that the one attached here (picture) is not reacting to UV at all.
I will test the RI when I'm back in my country, and update this post!

 

[chrono]

Flame fusion synthetic spinels might be detectible by checking the RI and SG which is slightly different from natural spinels but it isn't as easy for flux synthetic spinels. They show the same RI (~ 1.717) and SG (~ 3.60) as natural spinels. The spectroscope is of no help either, as both, natural and synthetic red spinels are coloured by chromium and show the same absorption lines (“organ pipes”) and bands. Between the crossed filters of a polariscope, the tested flux synthetic spinels all showed distinct anomalous extinction due to internal strain, which may also be observed in natural spinels, especially around inclusions. Under LW and SW ultraviolet, the stones generally exhibit a distinct orange-red fluorescence, sometimes slightly chalky yellowish orange along facet edges. But again, a safe detection based on these observations is not possible.

You can read more about the microscopic inclusions in the link below.
http://midtenn-gia-alumni.carrienunes.com/news/08-10_spinel.php

 

[_BUQARI_]

Flame fusion synthetic spinels might be detectible by checking the RI and SG which is slightly different from natural spinels but it isn't as easy for flux synthetic spinels. They show the same RI (~ 1.717) and SG (~ 3.60) as natural spinels. The spectroscope is of no help either, as both, natural and synthetic red spinels are coloured by chromium and show the same absorption lines (“organ pipes”) and bands. Between the crossed filters of a polariscope, the tested flux synthetic spinels all showed distinct anomalous extinction due to internal strain, which may also be observed in natural spinels, especially around inclusions. Under LW and SW ultraviolet, the stones generally exhibit a distinct orange-red fluorescence, sometimes slightly chalky yellowish orange along facet edges. But again, a safe detection based on these observations is not possible.

You can read more about the microscopic inclusions in the link below.
http://midtenn-gia-alumni.carrienunes.com/news/08-10_spinel.php

Thank you very much for your post!
Only "inclusion" I can see under 45x loupe is as pictured (figure 4).
So then I suppose it's a synthethic Spinel for sure ..

 

[chrono]

Buqari,
I am sorry the spinel turned out to be the new type of synthetic. I hope you are able to return the stone for a refund or at least did not pay a lot for it.

 

[_BUQARI_]

Buqari,
I am sorry the spinel turned out to be the new type of synthetic. I hope you are able to return the stone for a refund or at least did not pay a lot for it.

Thank you!
I did not pay a lot for this one.

I will get an AGL FastTrack Report for it just incase it might be real, approx $55.00 instead of the AGL Full Report.

 

[chrono]

A very good idea and I am thankful the AGL briefs are affordable!

 

[_BUQARI_]

A very good idea and I am thankful the AGL briefs are affordable!

I totally agree!