Post subject: Re: Natural, treated, synthetic sapphire????
Posted: Wed Apr 22, 2020 9:38 am
Gold Member
Joined: Thu May 12, 2016 2:18 am Posts: 1542
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.
Post subject: Re: Natural, treated, synthetic sapphire????
Posted: Sun Apr 26, 2020 5:23 am
Active Member
Joined: Sat Feb 08, 2020 9:09 am Posts: 73
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.
Attachments:
IMG_20200425_111625.jpg [ 1.32 MiB | Viewed 2037 times ]
IMG_20200426_103525.jpg [ 902.84 KiB | Viewed 2037 times ]
IMG_20200425_111521.jpg [ 1.61 MiB | Viewed 2037 times ]
Post subject: Re: Natural, treated, synthetic sapphire????
Posted: Sun Apr 26, 2020 5:53 pm
Gold Member
Joined: Mon May 26, 2014 9:42 pm Posts: 1033
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....
Post subject: Re: Natural, treated, synthetic sapphire????
Posted: Mon Apr 27, 2020 3:13 pm
Gold Member
Joined: Thu May 12, 2016 2:18 am Posts: 1542
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.
Post subject: Re: Natural, treated, synthetic sapphire????
Posted: Mon Apr 27, 2020 4:20 pm
Active Member
Joined: Sat Feb 08, 2020 9:09 am Posts: 73
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.
Users browsing this forum: No registered users and 7 guests
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot post attachments in this forum