December 14-16—SAN DIEGO, CALIFORNIA: Wholesale and retail show; Gem Faire Inc.; Scottish Rite Center, 1895 Camino del Rio S; Fri. 12-6, Sat. 10-6, Sun. 10-5
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 Post subject: Notice this on auction, and the title says GIA, but
PostPosted: Tue Aug 25, 2015 8:12 pm 
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The report says GLA (Gemological Laboratory International)
http://www.invaluable.com/auction-lot/4 ... 47b49c6a01

The stone is ugly in my opinion, and I am surprised color change from yellowish green to brown yellow would be considered an alexandrite. (Is any color change chrysoberyl called alexandrite?)

So here are my questions:
Are GLA and GIA the same?
What defines an alexandrite?


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 Post subject: Re: Notice this on auction, and the title says GIA, but
PostPosted: Tue Aug 25, 2015 9:00 pm 
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Here's a good hint that it's not legit (beyond saying GIA in the title. Not GlA, GIA):
their email address listed on the certificate is GLALaboratory AT gmail. GMAIL. Dear sweet goodness.
The GIA also won't appraise things.
That said, the GIA does not appear to be entirely above these kinds of shenanigans in declaring a chrysoberyl with a minor, non green-red directional color shift as Alexandrite: viewtopic.php?f=6&t=20374


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 Post subject: Re: Notice this on auction, and the title says GIA, but
PostPosted: Tue Aug 25, 2015 10:05 pm 
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That's messed up on so many levels.


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 Post subject: Re: Notice this on auction, and the title says GIA, but
PostPosted: Wed Aug 26, 2015 1:34 pm 
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dchallener wrote:
The report says GLA (Gemological Laboratory International)
http://www.invaluable.com/auction-lot/4 ... 47b49c6a01

The stone is ugly in my opinion, and I am surprised color change from yellowish green to brown yellow would be considered an alexandrite. (Is any color change chrysoberyl called alexandrite?)

So here are my questions:
Are GLA and GIA the same?
What defines an alexandrite?


This appraisal just references a GIA report. I don't see anything unusual about that, I have no comments on the rest of the appraisal though. As for the color change, even if it is less than a desirable red to green color change you would expect from the top tier of material, if it changes color and is chrysoberyl, then it is alexandrite. GIA issues identification reports, not quality reports on color stones. If a Burmese ruby comes into a lab loaded with cracks and looks like a piece of red road gravel and the client wants an origin report, it's still a Burmese ruby even if it doesn't match what people's perception of an ideal Burmese ruby should look like.

I hope that analogy makes sense.

Cheers,
Nathan

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 Post subject: Re: Notice this on auction, and the title says GIA, but
PostPosted: Wed Aug 26, 2015 5:37 pm 
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Actually Nathan, I don't think it does reference a GIA report.
I think it references a GlA report.

If you look very very closely, you will see that the middle letter there is a lower case L, not a capital i.


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 Post subject: Re: Notice this on auction, and the title says GIA, but
PostPosted: Wed Aug 26, 2015 7:00 pm 
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It's a real GIA report. You can enter the report number on the GIA website to confirm, and view the GIA report. It matches the appraisal.

As far as I can tell, the appraisal company is just using the GIA report to validate the ID of the stone for their appraisal. I don't see anything too concerning here.

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 Post subject: Re: Notice this on auction, and the title says GIA, but
PostPosted: Wed Aug 26, 2015 11:15 pm 
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Sure enough, Nathan - there is an actual GIA report there.

And it does call that kind of color shift alexandrite.

I am disappointed that they would.

I grew up believing that the color shift was green/blue to red/violet.

So it looks sort of like an emerald in the day and a ruby at night.

The color of that stone is .... ugly.

But as you say, their report is "just the facts, Ma'am" and the report includes the color (pictures even) right on it, so people shouldn't be deceived by it.


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 Post subject: Re: Notice this on auction, and the title says GIA, but
PostPosted: Wed Aug 26, 2015 11:28 pm 
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dchallener wrote:
The stone is ugly in my opinion, and I am surprised color change from yellowish green to brown yellow would be considered an alexandrite. (Is any color change chrysoberyl called alexandrite?)

What defines an alexandrite?


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As for the color change, even if it is less than a desirable red to green color change you would expect from the top tier of material, if it changes color and is chrysoberyl, then it is alexandrite.
I hope that analogy makes sense.
Cheers,
Nathan

I am sorry, but your explanation doesn't convience the gemologists that I know.
Unless I am wrong, chrysoberyl is a minerial and alexandrite is a color variety of that mineral which shows green and red - by definition because those colors related to the Czar.
Are you now trying to tell us that the GIA is unilaterially changing the definition of that material so that their reports will give a boost to the selling of crap?


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 Post subject: Re: Notice this on auction, and the title says GIA, but
PostPosted: Thu Aug 27, 2015 12:39 am 
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I agree with you Dr. Hanneman. The color shifting bug juice chrysoberyl the GIA is calling alexandrite is not what I would call alexandrite.....but no one called me for an opinion. I use the analogy of padparadsha to qualify my opinion of the importance of nuance of color in describing gems such as alex and pad.

I must say, I understand Nathan's position, and therefore, the GIA's position, just don't agree with it.


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 Post subject: Re: Notice this on auction, and the title says GIA, but
PostPosted: Thu Aug 27, 2015 1:57 am 
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Bill Hanneman wrote:
dchallener wrote:
The stone is ugly in my opinion, and I am surprised color change from yellowish green to brown yellow would be considered an alexandrite. (Is any color change chrysoberyl called alexandrite?)

What defines an alexandrite?


Quote:
As for the color change, even if it is less than a desirable red to green color change you would expect from the top tier of material, if it changes color and is chrysoberyl, then it is alexandrite.
I hope that analogy makes sense.
Cheers,
Nathan

I am sorry, but your explanation doesn't convience the gemologists that I know.
Unless I am wrong, chrysoberyl is a minerial and alexandrite is a color variety of that mineral which shows green and red - by definition because those colors related to the Czar.
Are you now trying to tell us that the GIA is unilaterially changing the definition of that material so that their reports will give a boost to the selling of crap?


No need to be sorry Bill, you are certainly entitled to your opinion and its not my intent to convince anyone of anything on the matter, I'm simply trying to offer some clarity. I am definitely familiar with both sides of this particular situation. If alexandrite must show a green to red color change, then I must admit.... I have NEVER seen a "true" "Czar-worthy" alexandrite. Those gems must be among the absolute rarest of colored stones.

However, its interesting that nobody seems to mind or complain about giving the rather attractive Brazilian blue-green to purple color changing Chrysoberyl an "Alexandrite" designation, so it seems reasonable to offer it's less desirable and sometimes "ugly" cousin, the Sri Lankan variety that goes from some shade of green to some shade of brown the same courtesy. Remember, its not a quality report and I imagine the Brazilian and Sri Lankan material entered the market after the Russian green changing to red stuff. If I had my way, I'd gladly call all of it color changing chrysoberyl, but gem dealers who are much better at marketing than myself wouldn't be very pleased.....Besides, I doubt the Czar cares too much about folks calling non-red color changing varieties of chrysoberyl "alexandrite" these days anyway. :wink:

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 Post subject: Re: Notice this on auction, and the title says GIA, but
PostPosted: Thu Aug 27, 2015 5:22 pm 
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Bill said>> Unless I am wrong, chrysoberyl is a minerial and alexandrite is a color variety of that mineral which shows green and red - by definition because those colors related to the Czar.

I'm with you Bill!

I looked it up in " a dictionary of mining, mineral, and related terms", published by the U.S. Department of the Interior, Bureau of Mines in 1968, and it says:
"A variety of chrysoberyl, emerald green in daylight and red to violet by ordinary artificial light"

A couple of dictionaries I looked up had the same definition.

I am willing (myself) to call teal a variety of green (well, really blue-green), as beryl that is teal is often called an emerald.
So the Brazilian stuff qualifies in my book.

But that picture? Nope.


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 Post subject: Re: Notice this on auction, and the title says GIA, but
PostPosted: Thu Aug 27, 2015 5:26 pm 
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Nathan Renfro wrote:
If alexandrite must show a green to red color change, then I must admit.... I have NEVER seen a "true" "Czar-worthy" alexandrite. Those gems must be among the absolute rarest of colored stones.

I believe they are, but keep looking, you are still young. :D :D
Quote:
However, its interesting that nobody seems to mind or complain about giving the rather attractive Brazilian blue-green to purple color changing Chrysoberyl an "Alexandrite" designation, so it seems reasonable to offer it's less desirable and sometimes "ugly" cousin, the Sri Lankan variety that goes from some shade of green to some shade of brown the same courtesy.

I believe that is a question of whether one is a buyer or a seller, and GIA is in the business of selling opinions. However, I and my ilk, do not think it is reasonable to change the meaning of well establish words in order to make a sale.
Quote:
Remember, its not a quality report and I imagine the Brazilian and Sri Lankan material entered the market after the Russian green changing to red stuff.

I believe that is a non sequitor, as I do not believe the color of a gem (red, blue, green or yellow) has anything to do with quality.
Quote:
If I had my way, I'd gladly call all of it color changing chrysoberyl, but gem dealers who are much better at marketing than myself wouldn't be very pleased…

But, true gemologists would be. However,there are some in the business world who would opine, “Follow the money, integrity be damned.” :(
Quote:
...Besides, I doubt the Czar cares too much about folks calling non-red color changing varieties of chrysoberyl "alexandrite" these days anyway. :wink:

True, but the Russian people are fond of RED. :D :D


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 Post subject: Re: Notice this on auction, and the title says GIA, but
PostPosted: Thu Aug 27, 2015 9:54 pm 
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True, but the Russian people are fond of RED


Hmmm... Who told you that, Dr. Hanneman? Russian people are honor the red! This color symbolizes the oceans of blood - the price of freedom of the Russian people, they paid for..

As for red color of Russian alexandrite... There is a little secret of this color.. Candle light... We can take any of brownish Lankian or Tanzanian alexandrite, and under candle light it will appear red. Other way - no one best Russian alexandrite will appear red under modern tungsten incandescent light... Always will be purplish.

My opinion - definition of all gemstones by the color has come to us from the depths of time, now, in the 21st century, it should be strictly scientific. Since chrysoberyl colored by traces of iron, rarely vanadium or chromium, and chromium is responsible for the effect of color change, then chromium should be the determining factor of chrysoberyl / alexandrite. If larger amount of iron make green color yellowish and "red' color" brownish, but still chromium is presented - then it is still alexandrite... I think it will be simple and clear...

As historical definition "green/red", then again - remember about candle. :)

Any historical definition can and must be changed since scientific reasons found. Not long ago blue color for garnet was just a joke...

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 Post subject: Re: Notice this on auction, and the title says GIA, but
PostPosted: Thu Aug 27, 2015 11:33 pm 
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GSK wrote:
There is a little secret of this color.. Candle light... We can take any of brownish Lankian or Tanzanian alexandrite, and under candle light it will appear red.

Not in my experience, no. Still purplish or brownish for the least-cooperative stones. My laser pointer sure brings out the color though! :lol:
GSK wrote:
My opinion - definition of all gemstones by the color has come to us from the depths of time, now, in the 21st century, it should be strictly scientific.

There's nothing particularly scientific about that. In this case, you're just using Cr presence as a proxy to try and get at the information we really want, which is whether the stone shows the requisite 'phenotype'--a color change from red-to-purple to green-to-bluegreen. The problem is that that proxy doesn't work, because other elements can totally mask the effect even if Cr does happen to be present in some amount. Similarly, the presence of Cr in beryl does not itself an emerald make--it can either be too little and give a pale color, or be overwhelmed by the presence of iron giving a blue color. Just because something is hard or expensive to measure and uses a totally rad instrument to do so doesn't mean that what you're measuring is inherently more 'scientific' or useful.
My primary concern here would be that the photos show what I would call a "color shift at best," not a proper color change at all. I wouldn't, for instance, sell my yellow spodumenes as "color change" even though they can go from pure yellow to yellow-green or from near-colorless to bright yellow when going from sunlight to fluorescent.


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 Post subject: Re: Notice this on auction, and the title says GIA, but
PostPosted: Thu Aug 27, 2015 11:46 pm 
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As i understand the color change is complete change of hue. The ruby also looks very different under different lighting conditions.. But nobody calls them as color change...

Yes, different element cam mask the "chromium effect", very correct. But no chromium content in chrysobelyl will make no any effect such as color change.. So maybe more correct would be say "alexandrite is the variety of chrysoberyll, chromium bearing and with noticeable color change of effect".

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