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 Post subject: Turquoise
PostPosted: Wed Mar 05, 2014 8:02 pm 
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sorting time. spring cleaning, as it were.
any tips separating natural from dyed from reconstituted from whatever else is out there? i'm terrible at turquoise. i've always said that there needs to be some kind of refresher course offered. but then again... IT'S TURQUOISE.
destructive tests welcome. seriously.
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 Post subject: Re: Turquoise
PostPosted: Thu Mar 06, 2014 4:54 am 
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Hi Jimsfault !

if you can read in French , here is an interesting thesis about Turquoise , from Claire Salanne _ DUG Nantes:

http://www.gemnantes.fr/documents/pdf/D ... ne_dug.pdf

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 Post subject: Re: Turquoise
PostPosted: Thu Mar 06, 2014 7:47 am 
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If RI < 1.58 or > 1.62 : not turquoise
If density > 2.9 or < 2.2 : not turquoise
hot needle test :stabilised ?
If reaction with HCl : not turquoise (carbonate, reconstituted…)
If reaction with aceton : dyed
check structure + inclusions with a microscope (glass, porcelain, synthetic, reconstituted...)

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Last edited by marcm on Wed Aug 30, 2017 1:59 pm, edited 1 time in total.

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 Post subject: Re: Turquoise
PostPosted: Thu Mar 06, 2014 11:40 am 
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Good answer Marc!


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 Post subject: Re: Turquoise
PostPosted: Thu Mar 06, 2014 8:19 pm 
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Thanks Mark.
I'm going with HCl. That's the one I was looking for.


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 Post subject: Re: Turquoise
PostPosted: Thu Mar 06, 2014 8:46 pm 
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Hello Danielle,

I am keeping the link as a reference for later. Good thesis on the subject. I have to much too learn for the moment to be so specific but I am really happy to have it for later. :D

Thank you very much.

Brigitte


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 Post subject: Re: Turquoise
PostPosted: Fri Mar 07, 2014 3:48 am 
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Hello Brigitte !

It was a pleasure to share . I'm glad you're happy to have it :)

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