Photoluminescence Spectra of Emeralds from Colombia, Afghanistan, and Zambia by Brian Thompson. See Research Below
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 Post subject: Re: Cristinite
PostPosted: Wed Jan 25, 2012 11:30 am 
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Can't wait to see what it looks like when he takes his time :shock: !

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 Post subject: Re: Cristinite
PostPosted: Thu Jan 26, 2012 10:30 am 
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just curious, what is called christinite ? is it CZ ?


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 Post subject: Re: Cristinite
PostPosted: Thu Jan 26, 2012 11:00 am 
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cascaillou wrote:
just curious, what is called christinite ? is it CZ ?


Cristinite is an entirely different synthetic to CZ.

From what I understand, it is reconstituted chrysoprase, made under specific lab conditions with some added dopants. Technically it could be synthetic transparent Chalcedony, however if they simply melted it, kept the silica and didn't get any crystallization, it would be glass.

Depending on the colour and batch, optical properties and SG do vary wildly.

It is made in Australia, and has a bit of a following with hobbyists, but at a similar price to synthetic spinel or CZ, is not super popular for jewelry.


Last edited by Lawrence on Thu Jan 26, 2012 7:22 pm, edited 1 time in total.

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 Post subject: Re: Cristinite
PostPosted: Thu Jan 26, 2012 11:14 am 
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I found a site selling the stuff:
http://www.gemcutter.com/cristinite.htm

I would be curious to have someone test the material with crossed polars and let us know the reaction.


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 Post subject: Re: Cristinite
PostPosted: Thu Jan 26, 2012 4:26 pm 
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Barbra Voltaire wrote:
I would be curious to have someone test the material with crossed polars and let us know the reaction.

Why bother? If it weren't glass, the "inventor" or some scientist would have written a technical article touting it as the only known gem material in that RI range that was not birefringent, and they would have published an X-ray diffraction pattern to prove it. :D


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 Post subject: Re: Cristinite
PostPosted: Fri Jan 27, 2012 3:21 pm 
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I'm curious to know what is the exact chemical composition (SiO2?), what are the dopants, what is the structure (amorphous, cryptocrystalline, or crystalline? isotropic or anisotropic?) and what's the fabrication process (fusion?).
If someone finds out let us know :-)


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 Post subject: Re: Cristinite
PostPosted: Sat Jan 28, 2012 10:55 am 
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Cristinite is a trade name for a variety of silica-based doped glasses of varying SG and RI, but all sold under the name "Cristinite". It's just a made-up name for marketing.
The material is cheap and easy to cut and polish if you are not too aggressive at the coarser stages, because it is rather brittle.

This makes it an ideal material for test cutting or maybe even earrings or pendants for re-sale, so long as the customer is warned "It's brittle!"

Wayne


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 Post subject: Re: Cristinite
PostPosted: Sat Jan 28, 2012 11:11 am 
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Wayne, thank you for the definitive answer.
Dr. Hanneman was correct and it is what I suspected as well.
Cristinite=GLASS.


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 Post subject: Re: Cristinite
PostPosted: Sat Jan 28, 2012 12:00 pm 
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Jeffrey Hunt wrote:
With a controlled RI this Cristinite is the perfect glass for what I was looking for with a test cut - I originally had this post under Synthetics and Treatments. :)
.


It was moved because the premise of the thread is not about "Cristinite: man-made glass", it is about lapidary.
:D


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 Post subject: Re: Cristinite
PostPosted: Mon Jun 11, 2012 8:11 pm 
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lightbender57 wrote:
Cristinite is a trade name for a variety of silica-based doped glasses of varying SG and RI, but all sold under the name "Cristinite". It's just a made-up name for marketing.
The material is cheap and easy to cut and polish if you are not too aggressive at the coarser stages, because it is rather brittle.

This makes it an ideal material for test cutting or maybe even earrings or pendants for re-sale, so long as the customer is warned "It's brittle!"

Wayne


I agree it is great fun to cut, & so easy to polish - I have cut several pieces and posted pictures of some them here...
It is not ideal, however, or even appropriate in my opinion, for any type of jewelry for re-sale. I have a pendant that I set and wear myself, and I love it, I but would never give or sell a piece to someone else. Drop it on your dresser once, and it's chipped. Been there. Not fun.


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