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 Post subject: Natural, treated, synthetic sapphire????
PostPosted: Tue Apr 21, 2020 3:40 am 
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Hello!
I need some help with this light pink sapphire. Is it natural, treated or synthetic?

It has an RI of 1.761-1.769
Moderate red/orange in LWUV
very weak orange/red in SWUV

This is the most visible inclusion, about 3,5 mm.

Grateful for any and all thoughts and opinions!


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 Post subject: Re: Natural, treated, synthetic sapphire????
PostPosted: Tue Apr 21, 2020 3:44 am 
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Stone above.


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 Post subject: Re: Natural, treated, synthetic sapphire????
PostPosted: Wed Apr 22, 2020 8:09 am 
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None of your pictures is helpful IMO.


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 Post subject: Re: Natural, treated, synthetic sapphire????
PostPosted: Wed Apr 22, 2020 8:32 am 
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What would be helpful, in your opinion?


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 Post subject: Re: Natural, treated, synthetic sapphire????
PostPosted: Wed Apr 22, 2020 9:38 am 
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We need a detailed high powered microscopic examination of the stone in order to determine natural/synthetic and treatments.

With the right equipment it may be possible to take good enough images. But if you had the equipment, you probably wouldn't need to us to make the determination.


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 Post subject: Re: Natural, treated, synthetic sapphire????
PostPosted: Wed Apr 22, 2020 9:59 am 
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Thank you, you are absolutely correct. Does it help that I know that the stone was cut and mounted before 1947?


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 Post subject: Re: Natural, treated, synthetic sapphire????
PostPosted: Wed Apr 22, 2020 2:04 pm 
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Synthetic Corundum has been around since 1873, so 1947 is not a reliable indicator.


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 Post subject: Re: Natural, treated, synthetic sapphire????
PostPosted: Wed Apr 22, 2020 2:23 pm 
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I agree that your original pictures don't help.

The native cutting style of the sapphire would be unusual for synthetic but definitely not definitive.

Tell me a little about the mounting it is in.
Was it re-set or original?
Any maker's marks or hallmarks on the piece?


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 Post subject: Re: Natural, treated, synthetic sapphire????
PostPosted: Thu Apr 23, 2020 5:21 pm 
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any reaction to a magnet (if its floated on Styrofoam on a bowl of water, does magnet push it away?)


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 Post subject: Re: Natural, treated, synthetic sapphire????
PostPosted: Sun Apr 26, 2020 5:23 am 
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Barbra Voltaire, FGG wrote:
I agree that your original pictures don't help.

The native cutting style of the sapphire would be unusual for synthetic but definitely not definitive.

Tell me a little about the mounting it is in.
Was it re-set or original?
Any maker's marks or hallmarks on the piece?


Thank you very much for your reply!

The sapphire is set in atleast 8 kt gold. It has no purity mark, but I did an acid test. At first I thought it was strange that there was no purity mark, but then I read that (in Sweden) as long as the piece had a makers mark, it was'nt requierd.

It has a maker's mark GHS, (Sandqvist Gerdt Hartvig) active in Sweden between 1918-1973.
There is also a town mark for Tärnaby (small swedish town) and a year mark U8 (1946).

To my knowledge the stone is in it's original setting. I have looked for signs of it being re-set. It doesn't look like it has, although I'm not sure what to look for. :?


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 Post subject: Re: Natural, treated, synthetic sapphire????
PostPosted: Sun Apr 26, 2020 5:29 am 
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dchallener wrote:
any reaction to a magnet (if its floated on Styrofoam on a bowl of water, does magnet push it away?)


Hi!
No or very, very, very weak diamagnetic respons to a magnet. Although, I don't have the 1/2"X1/2" N52 grade NIB cylinder.


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 Post subject: Re: Natural, treated, synthetic sapphire????
PostPosted: Sun Apr 26, 2020 5:53 pm 
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There was a recent post on using magnets for determining various things, and a diamagnetic response was an indicator of synthetic.
Gemmology Today March 2020 NP.pdf
"any magnetic attraction.... is proof that a sapphire is natural. a synthetic sapphire made by flame fusion... is diamagnetic. However low-iron natural sapphires from certain localities.... can show a diamagnetic response....

For more detailed information: https://www.gemstonemagnetism.com/sapph ... _ruby.html


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 Post subject: Re: Natural, treated, synthetic sapphire????
PostPosted: Mon Apr 27, 2020 2:24 pm 
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Thank you! I know this Web site, very interesting reading!


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 Post subject: Re: Natural, treated, synthetic sapphire????
PostPosted: Mon Apr 27, 2020 3:13 pm 
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There are a number of test that are indicative but not definitive. We all know that in the end, it will be a microscope in the hands of a trained Gemologist, that will be required to make the call between natural and synthetic sapphire.


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 Post subject: Re: Natural, treated, synthetic sapphire????
PostPosted: Mon Apr 27, 2020 4:20 pm 
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1bwana1 wrote:
There are a number of test that are indicative but not definitive. We all know that in the end, it will be a microscope in the hands of a trained Gemologist, that will be required to make the call between natural and synthetic sapphire.


I agree. I could just send it off to be looked at, but where is the fun in that? What would I learn? I will not bore you with my newly gained, yet still very limited, knowledge. But 4 months ago I did'nt even know rubys and sapphires are the same mineral. I choose to expand my knowledge. And frankly, my understanding is that this perticular forum topic was created to nudge people in the right direction.


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