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 Post subject: Unidentified Green Crystal
PostPosted: Mon Feb 12, 2018 1:51 pm 
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Need some help with that one...
i have a very limited info regarding the history of that crystal,
i just know,it was found in europe,cut and polished in to cabochon by the seller himself and found its way to me.
this is what i could find so far:
hardness- around 5
specific gravity-and i am hope i am not getting it wrong but i am getting results between 2.50-2.52
given a room for error, a"moonstone" maybe?
it have a very nice chatoyancy effect.
and that's about all i know...
*unfortunately i don't have a way to check Refractive index,so i need another options.


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 Post subject: Re: green crystal
PostPosted: Mon Feb 12, 2018 2:18 pm 
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Hi Dor!
Glad to see you back in the saddle.

One more test Look at the stone sideways with magnification.
I suspect you may have a piece of fiber optic glass.

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The profile with magnification has a honey comp effect with fiber optic.
Image


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 Post subject: Re: green crystal
PostPosted: Mon Feb 12, 2018 2:54 pm 
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Barbra Voltaire wrote:
Hi Dor!
Glad to see you back in the saddle.

One more test Look at the stone sideways with magnification.
I suspect you may have a piece of fiber optic glass.

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Image
The profile with magnification has a honey comp effect with fiber optic.
Image


Hi barbra,thank you for quick response.
i saw some of that round glass balls in the same color selling for a few $ in ebay,look similar,but who knows... its really hard to tell,just from looking,on the other side of the spectrum, i also saw jadite that look similar by naked eye...
is fiber optic glass have the same spacific gravity as i mention?
it does look like a real crystal to me,at least by its shape and the story i got from the seller. seems reliable.
not sure what you mean by " honey comp effect" what exactly should i look for?
edit:
ok i got it.
but that's not what i see here. its look more like vertical lines crossing the crystal ,not like a net.
not sure if the lines are not on the outer surface,from the polish. my loup is realy not so great...


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 Post subject: Re: Unidentified Green Crystal
PostPosted: Mon Feb 12, 2018 3:45 pm 
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Yep, the hardness of FOGlass is 5-6
The SG can vary from 2.3-4.5

Enlarging the pic you posted above, I found some glues.
Follow the lines as far as you can and view them sideways.

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 Post subject: Re: Unidentified Green Crystal
PostPosted: Mon Feb 12, 2018 4:02 pm 
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Barbra Voltaire wrote:
Yep, the hardness of FOGlass is 5-6
The SG can vary from 2.3-4.5

Enlarging the pic you posted above, I found some glues.
Follow the lines as far as you can and view them sideways.

Image


scratchs on outer surface,i think.i really can't see what you suggesting,only vertical lines running across and seems that they are from the inside. like needle inclusions,
but it may be me that can't see ir,and\or the equipment.


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 Post subject: Re: Unidentified Green Crystal
PostPosted: Mon Feb 12, 2018 5:25 pm 
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This feature is VERY small! It's there!
http://www.theimage.com/newgems/synthet ... etic5.html


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 Post subject: Re: Unidentified Green Crystal
PostPosted: Mon Feb 12, 2018 9:29 pm 
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Barbra Voltaire wrote:
This feature is VERY small! It's there!
http://www.theimage.com/newgems/synthet ... etic5.html


very informative example,thank you for the link.
i don't see any glue. nither any "net" alike pattern like you was suggesting.
i think i see inclusions inside (or gas bubles,honestly not sure). i'll try tomorow to take better pictures. just very very hard to catch them on camera.
any way of using spectrometer in this case? i tried,but i dont see any absorbtion/lines
just the normal spectrum under fluorescent light.


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 Post subject: Re: Unidentified Green Crystal
PostPosted: Mon Feb 12, 2018 10:54 pm 
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Nope. Just viewing with magnification
No glue involved here.
The hardness and SG of your unknown ( 8) It's not unknown to me. ) are also indicators of fiber optic glass.


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 Post subject: Re: Unidentified Green Crystal
PostPosted: Tue Feb 13, 2018 1:26 am 
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I think (outside of the truly bizarre) the only vague possibility for a natural stone showing this kind of very strong cat's eye with this vibrant green color could have been apatite (unlikely with such a vibrant green) but the SG eliminates that pretty well. Fiber optic glass is very popular and sold around the world--I've seen them offered as natural stones in a variety of settings online.


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 Post subject: Re: Unidentified Green Crystal
PostPosted: Tue Feb 13, 2018 1:45 am 
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Stephen Challener wrote:
I think (outside of the truly bizarre) the only vague possibility for a natural stone showing this kind of very strong cat's eye with this vibrant green color could have been apatite (unlikely with such a vibrant green) but the SG eliminates that pretty well. Fiber optic glass is very popular and sold around the world--I've seen them offered as natural stones in a variety of settings online.



Stephen Challener wrote:
I think (outside of the truly bizarre) the only vague possibility for a natural stone showing this kind of very strong cat's eye with this vibrant green color could have been apatite (unlikely with such a vibrant green) but the SG eliminates that pretty well. Fiber optic glass is very popular and sold around the world--I've seen them offered as natural stones in a variety of settings online.


i saw moonstones that look very similar... SG also more close to that i mention.
any way you are both probably right. just something dosent look right,i dunno i personaly never see glass that has a shape like that (exept maybe a sea/beach glass but that is not the case here)
usually this things are cut perfectly to cabochon or balls, right?
look at that-


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 Post subject: Re: Unidentified Green Crystal
PostPosted: Tue Feb 13, 2018 2:20 am 
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Fiber optic glass is very popular and it's available in all sorts of formats: cabochons, spheres, hearts, donuts, tumbles, carvings, etc etc etc.
Moonstone does come in green, but it's a relatively pale green paired with a golden sheen (which can be a star or cat's eye but not like this). I don't think it ever comes in a vivid green like this. I did see a very weird "plumbian orthoclase" from Australia at Tucson this year, with more even translucency and a more yellow-green color than normal amazonite, but even that, even if it had a strong cat's eye, wouldn't come close to this.


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 Post subject: Re: Unidentified Green Crystal
PostPosted: Tue Feb 13, 2018 11:09 am 
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Here is a pile of tumble polished fiber optic glass:
Image
I rest my case.


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 Post subject: Re: Unidentified Green Crystal
PostPosted: Tue Feb 13, 2018 11:37 am 
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For some context, a couple of green moonstones (orthoclase) are shown below. Exactly the pale green color and golden sheen described by Stephen.
Attachment:
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Under the right lighting conditions they do exhibit chatoyancy.
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Last edited by Brian on Tue Feb 13, 2018 11:40 am, edited 1 time in total.

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 Post subject: Re: Unidentified Green Crystal
PostPosted: Tue Feb 13, 2018 11:40 am 
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Yes, it seems so.
thank you both. :mrgreen:


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 Post subject: Re: Unidentified Green Crystal
PostPosted: Tue Feb 13, 2018 11:42 am 
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Thanks Brian. Yes, greenish moonstone does exist...but it doesn't approach the color possibilities of glass.


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