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 Post subject: Oiling warning
PostPosted: Sat Mar 30, 2019 3:08 am 
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Joined: Thu May 28, 2009 4:13 am
Posts: 146
Hi all,

While clarity enhancement with oil and/or resins is clearly old news, I think I should share this information with you.

We've seen quite a fair amount of undisclosed oiled spinels from Burma and Vietnam in our office, to the point that we don't even start negotiating until the stones have soaked in acetone for 24h.
We've seen a few tourmalines (rubellites and Paraiba) which had been clarity enhanced with either oil or opticon.

And now, this: Tanzanite. Yup, you've read that right. We were warned by a friend who's working for a lab in Bangkok about that. We started to put the tanzanites lots we were considering to buy in acetone and so far, 2 stones proved to have been oiled : fissures were clearly visible after a day in acetone (thanks acetone, you're my best friend!).

So yeah, while it's not a new issue overall, it's good to keep it in mind: anything with surface reaching fissures and cracks can be oiled. And it looks like it's trending now.


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 Post subject: Re: Oiling warning
PostPosted: Mon Apr 01, 2019 7:03 am 
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Joined: Wed Jul 22, 2015 6:39 am
Posts: 135
:shock: thanks for the warning.

I immediately turn down oiled rough but faceted gems are not as easy to tell at a glance unless as you say soaked in acetone.

Annoys me no end when I see a nice bag of glowing clean apatite rough then I place my hand in it and pull out a sticky hand covered in oil #-o


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