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Synthetic overgrowth on glass filled rubies
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Author:  Barbra Voltaire, FGG [ Mon Jan 14, 2013 4:17 pm ]
Post subject:  Synthetic overgrowth on glass filled rubies

Andy Lucas, the Product Manager for GIA Course Development gave a lecture to the alumni group here.
He stated, he has encountered glass filled ruby with synthetic overgrowth, trapping the glass within surfacing fractures.
:?:

Has anyone encountered some examples of this new treatment scenario?
Has anyone any experience with heat, ultrasonics, etc.?

Author:  Alberto [ Tue Jan 15, 2013 1:37 pm ]
Post subject:  Re: Synthetic overgrowth on glass filled rubies

uhm...............synthetic overgrowth...........quite interesting............i only wonder which kinda process was used to achieve that....... :smt017 ............definitely something that doesn't need for high temps.....................hydrotermal maybe?? :roll:
i would really love to see a sample.............
ciao
albé

Author:  Barbra Voltaire, FGG [ Tue Jan 15, 2013 3:36 pm ]
Post subject:  Re: Synthetic overgrowth on glass filled rubies

OK.....a little more insight into the process.

The procedure is similar to the flux healing of Mong Hsu ruby.
It is done on fashioned goods and apparently seals surface reaching glass filled fractures with the same sort of synthetic produced during flux healing.

This is not an "overgrowth", as it does not cover the entire ruby. It apparently just "caps" the glass filled fractures making it more impervious to chemical and physical assault.

This seems to be a new discovery by some of the treaters in Bangkok and to my awareness, there is nothing yet in the literature about this procedure.

But, as a refresher on the process of flux healing in Mong Hsu ruby, this article by Dick Hughes is a great help:
http://www.palagems.com/flux_healing.htm

Author:  Alberto [ Tue Jan 15, 2013 3:47 pm ]
Post subject:  Re: Synthetic overgrowth on glass filled rubies

ok, we definitely don't have enough elements to comment but........it's my understanding that temperatures involved in flux healing process are far higher than the ones reached in recent glass filled stuffs.............

ciao
albé

Author:  Tim [ Tue Jan 15, 2013 5:14 pm ]
Post subject:  Re: Synthetic overgrowth on glass filled rubies

What bothers me is the question: how is synthetic corundum gonna 'stick to' the glass areas?

Author:  Conny Forsberg [ Tue Jan 15, 2013 6:10 pm ]
Post subject:  Re: Synthetic overgrowth on glass filled rubies

I guess it does not stick to the glass but kind of adheres to the sides of the fissures building a "lid". Seems like overkill procedure as the standard signs of glass filling will still be there, inside the stone. Better from durability view but will it still be cheapo cheapo?
Also my concern is the same as Alberto, what happens to the glass at temperatures flux melting corundum?

Author:  michael_e [ Tue Jan 15, 2013 8:12 pm ]
Post subject:  Re: Synthetic overgrowth on glass filled rubies

It probably has something to do with the chemistry of the original glass filling and could involve this sort of material:
http://physicsworld.com/cws/article/news/2004/aug/11/glass-breakthrough

Author:  Barbra Voltaire, FGG [ Tue Jan 15, 2013 11:04 pm ]
Post subject:  Re: Synthetic overgrowth on glass filled rubies

Indeed, all our ducks are not in an empirical alignment here.

I would love to see some of this stuff.

Author:  Lee Little [ Wed Jan 16, 2013 8:38 am ]
Post subject:  Re: Synthetic overgrowth on glass filled rubies

I am yet to spot one but appreciate the heads up as this would be a confusing issue as I did not know this could be done. There would be no concern about the ruby sticking to the glass as it would bond well to the sides of the void since that will be Ruby to Ruby. Good to hear they can protect that glass, it should be a much more durable product, just too bad it will still have the bad word, 'glass' in it's description.

Author:  Conny Forsberg [ Wed Jan 16, 2013 9:51 am ]
Post subject:  Re: Synthetic overgrowth on glass filled rubies

And why would that be bad? I concider disclosure as mandatory but I'm sure you will find them without the disclosure. Will look for some when I get to BKK.

Author:  Lee Little [ Wed Jan 16, 2013 11:42 am ]
Post subject:  Re: Synthetic overgrowth on glass filled rubies

Hi Conny,
I would reason that most people will not like having the word 'glass' come out in a gem report simply because of the bad reputation that leaded glass Ruby has received throughout the gemological community as well as because glass has just never been a good seller in the gemstone business.
I wonder where they are doing the treatment, perhaps Chanthaburi will have some examples if you are going to search in Thailand. Best regards, Lee

Author:  Conny Forsberg [ Thu Jan 17, 2013 7:39 am ]
Post subject:  Re: Synthetic overgrowth on glass filled rubies

If there is glass in the stone I for sure would like to know. If I sold stuff like that I would tell my customers the truth, no fancy BS. Negative or not, I would like my customers to spend their money on the real deal and not buy gem wannabes so if the word glass makes them pass on the deal... Good for them.

Author:  Lee Little [ Thu Jan 17, 2013 8:20 am ]
Post subject:  Re: Synthetic overgrowth on glass filled rubies

Of course, you would want to know and of course, you would be straight with disclosing to your customers. I do not think there will be much issue with lack of disclosure on this treatment. On the wholesale level the sellers will really want the buyer to understand that the stone has had this advanced treatment rather than the stone being called a simple lead glass filled Ruby, which is likely what they look like with a 10x loupe. I don't think anybody will be able to not disclose this treatment when dealing with a knowledgeable buyer as glass most always has bubbles in it and a layer of Ruby over it will not hide that. Since leaded glass Ruby has such a bad name, owners of this treated gem will likely go to lengths to explain the treatment. Retail customers may still not get full disclosure every time but it will not be as bad a thing as the mess with LG Ruby since these would likely be more durable.
I wonder if they have any pockets that do not get protected by Ruby. If they do then they are not much better than the old LG Rubies. We will have to watch for more lab reports on this one.
It may also be tricky to differentiate one of these from a regular lead glass Ruby without a scope.
Now that I think about it, I may have already seen one of these, a Ruby that had both round air bubbles and flux veils. Best regards, Lee

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