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 Post subject: Unusual peridot, possibly treated?
PostPosted: Sat Oct 24, 2015 12:43 pm 
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Hey everyone. I came across an unusual stone at work the other day and wanted to get some thoughts on it. For all the world, the stone appeared to be peridot. There was strong birefringence, two lightly bubbled curtains and some lillypads, all inclusions I regularly see in peridot. But the COLOR was this dark almost (but not quite) chrome green. I've never seen a peridot this dark before. I had our GG look at it and he said it pulled a peridot RI.

Now, I know that peridot can sometimes be dark; I personally wear a necklace I made with a nice deep olive green one. But I've never seen or heard of a peridot being THIS dark. I've also never heard of peridot being treated for color in any way. So what say you? Can peridot be treated to a darker green? And is this done regularly? Could it be a surface coating, like is frequently done to topaz? The stone definitely wasn't a doublet; the veils in it ran vertically all the way through from the table to culet. Would love to hear your thoughts!

Thanks!

Edit -- Sorry for the crappy photo quality. I just took some quick ones through my scope with my cell phone. Also, for context, the ring is one of those made-in-thailand sterling ring with a heavy nickel or rhodium plating deals. The accent stones are CZ or white topaz.


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 Post subject: Re: Unusual peridot, possibly treated?
PostPosted: Sat Oct 24, 2015 3:59 pm 
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Peridot is not treated or enhanced in any way that's what i have heard. How old is your ring? any idea? Peridot does get scratches on surface table sometimes, but maybe your stone if real, it looks like a chrome diopside, may be i'm wrong though..
experts can tell you better.


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 Post subject: Re: Unusual peridot, possibly treated?
PostPosted: Sat Oct 24, 2015 5:24 pm 
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Maybe diopside. Or tourmaline. Both stones are strongly doubly refractive.
An RI and calculation of exact birefringence would help.


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 Post subject: Re: Unusual peridot, possibly treated?
PostPosted: Sat Oct 24, 2015 10:32 pm 
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Not peridot.

I'm not seeing any doubling of the back facets which would indicate a high birefringence.
Lily pads inclusions also display a profound doubling with magnification:
Bubbled veils? Nope....Perhaps liquid veils?
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 Post subject: Re: Unusual peridot, possibly treated?
PostPosted: Sun Oct 25, 2015 7:42 am 
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Actually Flameswithin, if you are not positive about the doubling, given the other specs of the ring (sterling + CZ + made in Thailand) this green stone might as well be glass or any man-made stuff.


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 Post subject: Re: Unusual peridot, possibly treated?
PostPosted: Sun Oct 25, 2015 12:34 pm 
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Isi...I was thinking glass too. :idea:
Rounded facet junctions, what appears to be conchoidal fracturing on the girdle......does look glassy.


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 Post subject: Re: Unusual peridot, possibly treated?
PostPosted: Sun Nov 01, 2015 2:33 pm 
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Hey everyone, thanks for your thoughts!

I didn't capture any of the things I described very well in the photos, but in person, there was a very pronounced birefringence. That being said, maybe chrome diopside is a posibility. I did not see any dichroism at all that would have suggested tourmaline, however.

I don't personally consider rounding of facet junctions as indicative of anything at this point. I routinely see amethysts, citrines, topazes, garnets, etc with rounded facet junctions. Commercially cut stones of *any* sort just aren't crisp. And i doubt production jewelers are particularly careful with their tripoli or rubber wheels which can make matters worse. The last two white moissanites I set at work showed rounding of their facet junctions, too.

All things considered though, I think you guys are right and it was probably a chrome diopside. My bad, thanks for your input! :)

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 Post subject: Re: Unusual peridot, possibly treated?
PostPosted: Sun Nov 01, 2015 5:14 pm 
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If you still have the unknown, I'd be happy to test it for you.
Price: Return Postage.

You have some pretty sassy pieces on your Etsy site. Outstanding!


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 Post subject: Re: Unusual peridot, possibly treated?
PostPosted: Fri Nov 06, 2015 12:53 am 
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Barbra Voltaire wrote:
You have some pretty sassy pieces on your Etsy site. Outstanding!

And he test-cuts so many of my designs without complaint as well! Phil's such a good guy :)


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