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 Post subject: Fluorite threelobes
PostPosted: Tue Sep 19, 2017 5:29 am 
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Joined: Sat May 21, 2011 7:09 am
Posts: 77
Location: Italy
HI,

I own some violet cabs: at first look, they look like amethyst.
Image
After investigation, S.G. and R.I. (spot reading) are in the range of fluorite.
Under LW UV the stones are fluorescent and at 130°C they are thermoluminescent.

Under microscope, the color zoning are different from the others fluorite I have seen.
Image

I mean color zones are in the shape of "threelobes".
Image
A little help:
Image

Image

Any comment will welcome.


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 Post subject: Re: Fluorite threelobes
PostPosted: Tue Sep 19, 2017 3:26 pm 
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Joined: Mon Apr 02, 2012 9:31 pm
Posts: 4015
Location: North Carolina
'Mercedes logo' zoning is sometimes seen at larger scales in fluorite, particularly Illinois ones. Here's one from Spirifer minerals:
Image
I've never seen them at this scale though--that's really interesting!

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