Coming Soon!!! Gem Identification Instrument Give-Away. Donated by W.Wm.Hanneman
Welcome to the GemologyOnline.com Forum
A non-profit Forum for the exchange of gemological ideas
It is currently Fri Feb 22, 2019 4:34 pm

All times are UTC - 4 hours




Post new topic Reply to topic  [ 3 posts ] 
Author Message
 Post subject: Topaz from Tarryall Mts., CO.
PostPosted: Sun May 27, 2018 8:22 pm 
Offline
Site Admin
User avatar

Joined: Sun Oct 16, 2005 12:22 pm
Posts: 19378
Location: San Francisco
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?


Attachments:
topaz.jpg
topaz.jpg [ 284.11 KiB | Viewed 166 times ]
Top
 Profile  
Reply with quote  
 Post subject: Re: Topaz from Tarryall Mts., CO.
PostPosted: Sun May 27, 2018 8:53 pm 
Offline
Moderator
User avatar

Joined: Mon Apr 02, 2012 9:31 pm
Posts: 3154
Location: North Carolina
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.

_________________
https://www.etsy.com/shop/angryturtle


Top
 Profile  
Reply with quote  
 Post subject: Re: Topaz from Tarryall Mts., CO.
PostPosted: Sun May 27, 2018 10:41 pm 
Offline
Gemology Online Veteran
User avatar

Joined: Tue Jan 31, 2006 12:38 pm
Posts: 884
Location: N.J.
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.

_________________
Nick


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 3 posts ] 

All times are UTC - 4 hours


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
Gemology Style ported to phpBB3 by Christian Bullock