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 Post subject: Madagascar Sapphire: Low-Temperature Heat Treatment
PostPosted: Mon Aug 19, 2019 3:12 pm 
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Madagascar Sapphire: Low-Temperature Heat Treatment Experiments
by E. Billie Hughes and Rosey Perkins


ABSTRACT
Madagascar has become one of the world’s top sources of fine blue sapphire in recent times. In addition to beautiful untreated material, increasing numbers of treated stones have appeared in the market. Some have been heated to relatively low temperatures, below 1350°C, to lighten their color. To help separate unheated and heated Madagascar sapphire, the authors performed experiments to document the changes they undergo with low-temperature heat treatment in air, which is an oxidizing atmosphere.
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 Post subject: Re: Madagascar Sapphire: Low-Temperature Heat Treatment
PostPosted: Wed Oct 16, 2019 11:18 am 
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Oh, I didn't know that Madagascar had a lot of sapphire deposits... I guess I'll go to bed smarter today!
And if they're able to provide quality gems to the market, then everybody wins. Should we await changes in prices or will it remain as it is now?


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 Post subject: Re: Madagascar Sapphire: Low-Temperature Heat Treatment
PostPosted: Thu Oct 17, 2019 2:05 pm 
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A little more information:

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Field Gemology by Vincent Pardieu

Dear all,
I'm happy to invite you to discover another new field video on my YouTube Channel: In this short video you will discover what we saw on our recent visit to the Ilakaka sapphire producing area in southern Madagascar in May 2018. The main objective for that field expedition was to collect reference samples for the "Bahrain Institute for Pearls & gemstones (DANAT)". During that expedition we visited two new sapphire producing areas near Ilakaka town where gem rushes were ongoing:
- First at Belamoty, on the extrem south of the deposit,
- Then at Ambarnakuhy, few kilometers north of the road linking Ilakaka and Sakaraha.
In both places we found out that several thousands of unlicensed miners had moved there to work and get sapphires. If the mining activity around Ilakaka has reduced compared to the period in the early 2000's still several tens of thousands of people are working different areas in this vast region that will probably continue to produce sapphire for many many years.

Many thanks for this video to Anthony Methez (from Nomads Drone) and Philippe Brunot, who were my cameramen on that field expedition and to all the people we met in Madagascar for their welcome and support and more particularly to Marc Noverraz from Colorline Madagascar and to Nirina Rakotosaona.

Enjoy


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Field Gemology by Vincent Pardieu

In December 2018 we visited the Antaralava mining area north of Sakaraha in Madagascar as an important gem rush occurred there since the beginning of the year attracting several thousands of small scale unlicensed miners. Going there was not easy as the area was notoriously plagued by bandits. With the help of the authorities and our local friends, we were nevertheless able to access to the remote mining village and witness the mining site on the Fiherenana River. Mining there is quite difficult as the sapphire rich gravel layer is often under the water table and Malagasy small scale miners don't have pumps strong enough to work more than 1 or 2 meters under that water table. Nevertheless we could once again collect some interesting reference samples for the "Bahrain Institute for Pearls & Gemstones (DANAT)".



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 Post subject: Re: Madagascar Sapphire: Low-Temperature Heat Treatment
PostPosted: Tue Nov 26, 2019 9:36 am 
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Oh, sorry, I've seen your answer only now.
Thanks for the very informative articles and videos!


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 Post subject: Re: Madagascar Sapphire: Low-Temperature Heat Treatment
PostPosted: Tue Nov 26, 2019 1:16 pm 
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My pleasure


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