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 Post subject: Topaz from Tarryall Mts., CO.
PostPosted: Sun May 27, 2018 8:22 pm 
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A client submitted a 31 carat golden sherry yellow topaz allegedly from Tarryall Mts., CO.
No chromium per raman therefore, not imperial.
If this topaz IS from Tarryall, should we (could we) expect fading?
Opinions on the stone?


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 Post subject: Re: Topaz from Tarryall Mts., CO.
PostPosted: Sun May 27, 2018 8:53 pm 
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I would guess fading is a strong possibility. I have heard some Colorado topaz fades and some does not, and in particular that the tribute pocket material was less stable than some other finds of brown colorado topaz, but in the past I have found people's reports of completely stable brown topaz to often be exaggerated. The only material I have personally tested that I would call stable has been Guerrero topaz from Mexico, and only some of that. Then again that was tested by leaving the stines outside in direct summer sunlight for a month, fairly harsh and maybe unrealistic. Still, it is definitely possible that it won't fade, or if so, so slowly it won't realistically be a problem. Certainly even among unstable topaz some fades much faster than others--irradiated Skardu topaz for isntance seems to go quite quickly in direct sunlight.

Fading question aside, that is a truly lovely stone. In my opinion a true beauty, easily worth the minor extra hassle of avoiding excess uv just in case.


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 Post subject: Re: Topaz from Tarryall Mts., CO.
PostPosted: Sun May 27, 2018 10:41 pm 
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I have also heard that most of the champagne Colorado topaz fades but a small amount does not. Most of what I have seen from the Tarryall mountain area has been white or a nice pale blue. I was looking at some photos of champagne stones that a Colorado dealer had for sale. He stated that the stones are much lighter in color now compared to when the photos were taken.

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