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Mystery green stone
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Author:  Debbie K [ Tue Feb 26, 2019 9:48 pm ]
Post subject:  Mystery green stone

Someone gave me this stone a while back and I assumed by looking at it that it was a tourmaline; it's a blueish-green color and seemed to have rod-like inclusions. I was reading an article that said that crystals could interfere with the tourmaline growth and create the rods, so decided to take a closer look (for crystals).

The inclusions look more like asbestos or something similar, so I started looking around for tourmaline inclusions online and in my books and couldn't find anything that looked like them. The inclusions open up like a fan towards their end.

Did a specific gravity and it came in at 2.53. At this point, did an RI (a spot reading) and it seemed to be around 1.49 - 1.50. I thought I detected a flicker, so pulled out the polariscope and it seems to be an SR stone. It stayed bright all the way around, but I've had inclusions trick me before. But I couldn't detect a change in the clear areas, either. Hardness is a little less than quartz, about the same as feldspar.

So here it is; about 38 carats and measures about 1.25" x .5" x.5". These are about the best I can get with the little Celestron microscope. The first two show close ups of the inclusions and the last one the whole stone. I saw one tiny bubble at the center of the star shaped one. Couldn't get a really good view of the dark spot to see whether or not it was a crystal.

Do you guys think this could be some really good glass of some kind? It seemed a little too hard, and the RI didn't look weird like it often does when it's glass. I haven't pulled out the lab spectroscope or the microscope yet, but probably will. If you guys can tell me anything I should be looking for or at, I'd appreciate it. Does anyone know what these inclusions might be?

Thanks in advance,

Debbie

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Author:  dchallener [ Tue Feb 26, 2019 10:42 pm ]
Post subject:  Re: Mystery green stone

How accurate is the color? the first thing that comes to mind with asbestos and green stone is serpentine.

Author:  Debbie K [ Tue Feb 26, 2019 10:53 pm ]
Post subject:  Re: Mystery green stone

It is a lovely slightly bluish-green. The Celestron has little LED lights which distort the color a little. The color is like a Colombian emerald.

I thought of Vesuvianite, but the RI and SG are wrong. The Canadian stuff is from an asbestos mine and that would fit, but it really seems to be an SR stone. The color of mine is very similar to this, but deeper. https://www.mindat.org/photo-63410.html

What kind of serpentine were you thinking it could be?

Debbie

Author:  Stephen Challener [ Wed Feb 27, 2019 12:42 am ]
Post subject:  Re: Mystery green stone

Everything comes up glass. The inclusions look like typical devitrification features, so I was thinking glass before the other data backed it up.

Author:  Debbie K [ Wed Feb 27, 2019 12:51 am ]
Post subject:  Re: Mystery green stone

Stephen:

Thank you! I think you're right; found this image once you said the magic words "glass devitrification" http://static.wixstatic.com/media/46200 ... 1.jpg_1024 This looks like what I'm seeing in this "stone".

Debbie

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