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 Post subject: Polariscope made of tourmaline
PostPosted: Fri Feb 09, 2018 12:28 pm 
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I don't really know where to post this question.
I have just read an old jewellery technique book, dating back from 1930 - 1940.
One chapter about gemological tools mentions a polariscope (it was not named so at that time) made of two tourmaline slices in crossed positions instead of our modern polarized filters.
Has anybody heard of this old device ?
Would that work fine ?


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 Post subject: Re: Polariscope made of tourmaline
PostPosted: Fri Feb 09, 2018 2:01 pm 
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Interesting. Tourmaline is the classic example of a polarizing crystal, so it should work. Polaroid film is a heck of a lot cheaper, though :-)


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 Post subject: Re: Polariscope made of tourmaline
PostPosted: Fri Feb 09, 2018 2:03 pm 
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They were called "tourmaline tongs"
http://physics.kenyon.edu/EarlyApparatus/Polarized_Light/Tourmaline%20Tongs/Tourmaline_Tongs.html

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 Post subject: Re: Polariscope made of tourmaline
PostPosted: Fri Feb 09, 2018 3:09 pm 
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Great information ! :P
Thanks Maialetto !


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