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Is GIA 100% reliable when it comes to colored stones?

tonyjlopez

Rough_Rock
Joined
Feb 5, 2013
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Hello everyone. Haven't posted here for many years but these forums were very helpful to me when I bought my wife a 20th anniversary diamond so I thought I would reach out again. We have a Red-Orange 6.62 carat sapphire that belonged to my wife's grandmother and has been in her family since at least the 1940's. It is an important family heirloom with memories and sentimental value to my wife mostly because her Mother wore it for many decades before she passed away in 2010. It was in a simple setting for decades and my wife never wore it because of the old fashioned setting. My wife always loved the stone however, as it is beautiful, and has a few microscopic chips and a scratch on the table from being much loved by her mother. She always wanted to put it in a newer setting so we recently had it reset in a halo setting as seen in the photos so she could wear it and enjoy it.

So the background on the stone. We have an old 1977 appraisal from my Mother-in-law valuing the sapphire in the setting at $3500. Around 2003, we decided we needed a new appraisal for insurance purposes. I brought it to Sotheby's jewelry through a contact I knew. Their jewelry expert evaluated and tested the stone and said it was genuine padparadscha sapphire and valued it at $35,000-$50,000 but told us we needed to have it checked and tested specifically for heat treatment in order to get an accurate appraisal. So a decade or so went by and we finally got around to removing the stone from the setting and getting the loose stone sent to GIA in 2012 to have them evaluate it for heat treatment. Long story short-they declared that it was a synthetic stone grown in a laboratory. A copy of the certificate is also posted.

At this point it only matters what it actually is for insurance reasons because my wife decided as you see to have it reset. The stone is beautiful in hand and has some interesting color play from orange to red and tinges of pink from different angles to my novice eye. We have no idea what an 80+ year old synthetic sapphire is worth if anything, but we never bothered to insure it after the GIA certificate was issued, assuming it has minimal value as a synthetic stone. We set it aside and only came across it recently stashed in the back of a drawer. Happy about finding it my wife made the decision to finally have it put in a new more modern setting.

So I've always wondered; is it possible that GIA got it wrong? The person at Sotheby's felt strongly about the authenticity and value of the stone (if not heat treated) so we were a little shocked a GIA's conclusion. Worth noting that GIA do not tell us in any of their paperwork why they determined it was synthetic and what testing/evaluation process they used to make that determination. No comments came back regarding heat treatment.

Is it possible they were less than thorough? Have you ever known them to make a mistake in concluding that a sapphire was synthetic? Is there any other laboratory that specializes in colored stone besides GIA that we should consider sending it to? I would appreciate thoughts and input. Ultimately it doesn't matter because it is still a sapphire and the outcome does not effect the sentimental value, which is priceless. Unfortunately we cannot insure for sentimental value, and we don't want to fail to have it properly insured if there is a remote possibility that GIA made a mistake.

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That colour screams strongly of synthetic, more so in that size. No lab is 100% infallible so if you are in doubt, you can send it to a second lab.
 
It is highly unlikely they would have a false synthetic conclusion but nothing is ever 100%.
 
My first though was synthetic pad. Typical strongly orange, too clean to be natural type of stone.

Then I read your post. The Sotheby person seems to have no clue or is being dodgy. I would personally not spend extra money for a second report, but if you need to do so to feel safer, why not.

Regardless of the outcome, thank you for posting and welcome back to the forum!
 
im not normally a halo girl but that ring is a knock out !
love the colour, regardless
its a beautiful stone
 
Sounds like there was a gap of at least 10 years between Sotheby's examination and GIA's report -- I am wondering if during that 10-year+ period colored gemstone/sapphire testing technology & techniques became more precise/thorough/sophisticated, which could account for the two different opinions in two different decades (?)
 
No lab is infallible but in this instance I would say it's likely that GIA is correct. The red/orange colour of this sapphire just screams BE treatment to me and I would tend to be more suspicious of this colour than say if I had a blue sapphire. Personally I wouldn't get a second report for the suspicious red/orange/yellow shades of sapphire of they've been assessed as synthetic or BE treated by GIA.
 
It looks synthetic to me with the color. I highly doubt the Sotheby's person was correct in this case and trust GIA
 
Curious about this "Sotheby's contact." Was this someone who was interested in auctioning the stone or was this a friend of a friend who worked in the mailroom? I am not familiar with Sotheby's offering drive-by opinions and appraisals but maybe they did. And I can't imagine a colored-stone expert referring to an orange-red gem as a padparadscha. Is there any paper trail of that -- or is it all word-of-mouth?

And are you confident about the "chain of custody"? I lost track of how many times it has been out of the mounting and for how long and in whose possession. If it was always known as 6.62 cts, like it is now, then I think it's highly unlikely to have been swapped out. But if there is no prior record, who knows. They certainly weren't diffusing gems in the '40s but maybe by 2012.

It is a pretty ring, though!

EDIT: maybe @PrecisionGem knows something about this type of material...?
 
While they may not have had diffusion that many years ago, it is the case that synthetic sapphires were certainly used frequently in high end jewelry of that time. Like the chorus of others, I bet on synthetic as well.
 
Curious about this "Sotheby's contact." Was this someone who was interested in auctioning the stone or was this a friend of a friend who worked in the mailroom? I am not familiar with Sotheby's offering drive-by opinions and appraisals but maybe they did. And I can't imagine a colored-stone expert referring to an orange-red gem as a padparadscha. Is there any paper trail of that -- or is it all word-of-mouth?

And are you confident about the "chain of custody"? I lost track of how many times it has been out of the mounting and for how long and in whose possession. If it was always known as 6.62 cts, like it is now, then I think it's highly unlikely to have been swapped out. But if there is no prior record, who knows. They certainly weren't diffusing gems in the '40s but maybe by 2012.

It is a pretty ring, though!

EDIT: maybe @PrecisionGem knows something about this type of material...?

Other than when it was at GIA and just now for the new setting we have been in posession of it since it was given to my wife by her Mother about 20 years ago. I personally brought it to Sotheby's in San Francisco and was there while she tested and examined it in the original setting. It was a loose stone from 2012 until last week when it was reset.

I am curious about the age of the stone and if there is a difference between synthetic stones created in the 1940's vs today. The images I took do not reflect the color well in hand it is lighter. I will try to take and post a video to see if that better represents the stone in-hand.
 
The first synthetic corundum, a flux-grown ruby, was produced in 1873. This development was followed by the commercial introduction of the flux-grown Geneva synthetic ruby in 1885 and Verneuil flame-fusion synthetic ruby in 1902.

Today the flux (solution) and Verneuil (flame-fusion) techniques are still used for synthetic gems and for other applications. During the 20th century, Carroll Chatham developed high-quality flux techniques to slowly grow crystals with carefully controlled properties. Using his specialized processes, Chatham introduced gem-quality ruby in 1959 and blue sapphire in 1975 (figure 4). Flame-fusion techniques have been used to quickly produce small sapphire boules used for jewelry as well as feed-stock for other sapphire growth techniques. Hrand Djevahirdjian began growing crystals using the Verneuil method in 1905, and the Swiss factory he opened in 1914 is still producing synthetic sapphire today

from:

So synthetic is absolutely possible.
 
Another inexpert opinion but this also looks to be synthetic to me. I have bought a LOT of sapphires over the years and many pads and this is not one. So sorry.
 
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