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 Post subject: Green Tiger-eye jade
PostPosted: Sun Jun 20, 2010 11:23 am 
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I recently bought from a dealer in Thailand (very cheap) what was described as a "Green tiger-eye jade" bracelet. Upon asking for more details, he said he doesn't know exactly, but it is a "colored jade."
Testing the bracelet, I get a spec. grav. of 2.45 and a RI of 1.776 .
What could it be?


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 Post subject: Re: Green Tiger-eye jade
PostPosted: Sun Jun 20, 2010 3:45 pm 
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Just guessing, but it might be a type of crystalline quartz :|

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 Post subject: Re: Green Tiger-eye jade
PostPosted: Sun Jun 20, 2010 3:49 pm 
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Yes, but, look at the values for SG and RI.


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 Post subject: Re: Green Tiger-eye jade
PostPosted: Sun Jun 20, 2010 3:57 pm 
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Location: The frozen north prairie :-/
Yeah, just looked again #-o . The only other thing I can think of with the RI/SG range would be glass. I'm not the sharpest knife in the drawer, though, so perhaps someone else can be more helpful :oops: .

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 Post subject: Re: Green Tiger-eye jade
PostPosted: Mon Jun 21, 2010 12:04 am 
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I would question whether your analytical results are correct.
How did you determine the RI of the curved surface?
Have you considered the sample might not be homogeneous—something like an organic polymer filled jadeite?


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 Post subject: Re: Green Tiger-eye jade
PostPosted: Mon Jun 21, 2010 4:18 am 
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The bracelet is round, yes, but it is totally composed of flat surfaces in the 3-5mm range, which are difficult to see on the photo I attached. I got a good line. As far as organics or colouration is concerned, I've had the bracelet in acetone for at least 5 minutes - no attack of the bracelet, no colouration of the acetone.


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 Post subject: Re: Green Tiger-eye jade
PostPosted: Mon Jun 21, 2010 4:20 am 
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.... that is, I got a good line reading on the hand-held diffraction refractometer.


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 Post subject: Re: Green Tiger-eye jade
PostPosted: Mon Jun 21, 2010 4:21 am 
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hi,

about taking RI, did you used the spot system? did you took multiple consistent values in different part of the bracelet?
ciao
alberto

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 Post subject: Re: Green Tiger-eye jade
PostPosted: Mon Jun 21, 2010 4:39 am 
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The spot system wasn't necessary, as I maneged to carefully find one of the small flat surfaces. I measured at least 4 times around the bracelet, all readings consistently about 1.775 .


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 Post subject: Re: Green Tiger-eye jade
PostPosted: Mon Jun 21, 2010 5:14 am 
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Both SG and RI are consistent with glass, even if the RI is a little bit high...

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 Post subject: Re: Green Tiger-eye jade
PostPosted: Mon Jun 21, 2010 12:38 pm 
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What's that bracelet look like under a microscope ? All of the natural materials that I've seen looking like that will show some evidence of a granular crystalline nature when looked at closely and with transmitted lighting. I've never seen glass have that granular look. I would think that glass would be obvious under a microscope, particularly in the areas with a dramatic change in color.

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 Post subject: Re: Green Tiger-eye jade
PostPosted: Tue Jun 22, 2010 12:55 pm 
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Under the binocular microscope, no evidence of grainy texture, not even in the colour change areas. I now think it must be a glass.


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 Post subject: Re: Green Tiger-eye jade
PostPosted: Tue Jun 22, 2010 3:29 pm 
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FYI, RI of glass can go up to 2.1 currently. I have some here currently that is 1.9.

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 Post subject: Re: Green Tiger-eye jade
PostPosted: Tue Jun 22, 2010 8:11 pm 
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It has patterns like agate - just the wrong color...and many of those bracelets are agate.

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 Post subject: Re: Green Tiger-eye jade
PostPosted: Wed Jun 23, 2010 12:17 am 
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It also has patterns that are typical of flow lines in glass.

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