Photoluminescence Spectra of Emeralds from Colombia, Afghanistan, and Zambia by Brian Thompson. See Research Below
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 Post subject: Vanadium and Chromium-Bearing “Color-Change” Pyrope Garnet
PostPosted: Wed Jan 20, 2016 9:01 pm 
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http://www.gia.edu/gia-news-research/va ... ope-garnet

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 Post subject: Re: Vanadium and Chromium-Bearing “Color-Change” Pyrope Garn
PostPosted: Thu Jan 21, 2016 4:39 am 
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That is beautiful material!
Thanks for sharing.

Do you know what main pavilion and crown angles were used in cutting these?


Last edited by Michael P. on Thu Jan 21, 2016 5:43 pm, edited 1 time in total.

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 Post subject: Re: Vanadium and Chromium-Bearing “Color-Change” Pyrope Garn
PostPosted: Thu Jan 21, 2016 5:26 pm 
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Can you tell me the RI's of those 5 garnets?


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 Post subject: Re: Vanadium and Chromium-Bearing “Color-Change” Pyrope Garn
PostPosted: Thu Jan 21, 2016 11:01 pm 
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This material showed a pretty consistent 1.736 RI for all the samples tested. However, the stones tested for the study don't include the large 5 pieces in the lead photo.

There is a red button to download the full paper at the above link.

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 Post subject: Re: Vanadium and Chromium-Bearing “Color-Change” Pyrope Garn
PostPosted: Thu Jan 21, 2016 11:58 pm 
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When you open Nathan's link above, click on the Download PDF red button to read the full article:
Image


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 Post subject: Re: Vanadium and Chromium-Bearing “Color-Change” Pyrope Garn
PostPosted: Fri Jan 22, 2016 2:13 am 
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Michael P. wrote:
That is beautiful material!
Thanks for sharing.

Do you know what main pavilion and crown angles were used in cutting these?


Sorry, I don't know what the main crown and pavilion angles are on those stones.

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 Post subject: Re: Vanadium and Chromium-Bearing “Color-Change” Pyrope Garn
PostPosted: Fri Jan 22, 2016 4:52 am 
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Nathan Renfro wrote:
There is a red button to download the full paper at the above link.


Er, Thanks! havn't seen this :oops:

The paper does answer my question about cutting angles as well.
35° crown angle, 38.5° pavilion angle.

Thanks for sharing this!


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 Post subject: Re: Vanadium and Chromium-Bearing “Color-Change” Pyrope Garn
PostPosted: Mon Jan 25, 2016 5:37 pm 
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Nathan Renfro wrote:
This material showed a pretty consistent 1.736 RI for all the samples tested. However, the stones tested for the study don't include the large 5 pieces in the lead photo.

Thanks. Look me up at Tucsun and we can talk.


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 Post subject: Re: Vanadium and Chromium-Bearing “Color-Change” Pyrope Garn
PostPosted: Thu Mar 23, 2017 4:14 am 
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We can also find this kind of material in Madagascar, nearby Fort Dauphin.


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