Presidium gem tester

Discussion in 'Jewelry' started by KSW, Aug 16, 2019.

  1. KSW

    KSW Well-Known Member

    judy likes this.
  2. Miscstuff

    Miscstuff Sometimesgetsitright

    Don't know the product but not keen on the idea of thermal absorption for coloured gems. Much prefer a refractometer and a polariscope as well as a microscope to do my identification. :)
     
    KSW and judy like this.
  3. KSW

    KSW Well-Known Member

    That sounds all very technical.....:pompous:
     
    Fid and judy like this.
  4. Miscstuff

    Miscstuff Sometimesgetsitright

    Yes it has to be as the fakers are seriously good at what they do. To fool this tester just a thin slice or a faceted crown of the desired material on the top of a faceted stone in its setting is all that is needed. Some diamond fakes have just the faceted crown glued on to the fitting so being able to test all round the stone can be important too.
     
    Fid likes this.
  5. KSW

    KSW Well-Known Member

    I'm not a jeweller and just want something to give me an idea of what I have. Don't think I have gems in that sort of league!
     
    kyratango likes this.
  6. Any Jewelry

    Any Jewelry Well-Known Member

  7. Fid

    Fid Well-Known Member

    sooooo...could you recommend affordable models for non-professionels ? I often thought about it as well but what I find costs an arm and a leg. cheers.
     
    kyratango likes this.
  8. Miscstuff

    Miscstuff Sometimesgetsitright

    Learning how to test is like any hobby - antiques - astronomy - restoration etc it take time and experience. These days you can buy some quite cheap analytical gear like refractometers and polariscopes etc on eBay ..
    https://www.ebay.com/itm/Gem-Refrac...252549?hash=item1a78e264c5:g:aSIAAOSwwKhcmJrh
    and also
    https://www.ebay.com/itm/Polariscop...291374?hash=item1c8a8895ee:g:vAwAAMXQAMlRYQMf
    https://www.ebay.com/itm/Pro-Gem-Ta...019617?hash=item469042fba1:g:-ZwAAMXQKQhRG5hM
    and you find the data all over the net
    https://www.gemsociety.org/article/table-refractive-index-double-refraction-gems/
    Also googling "gemstone inclusions" helps ID stones.
    Then you join a gemology forum and ask questions about identification problems you might have. You are also allowed to drool over some the gems shown by members.
    https://www.gemologyonline.com/Forum/phpBB2/viewforum.php?f=61&sid=19262c507cc64bcbb31454f92c62100f
    As for myself I did 99% of the "Colored gemstone" course at the Gemological Institute of America" in the late 1980s but ran out of money and had to come home. This was before they went bust and were bought out by the jewelry industry and all the settings they referred to as fraudulent and deceptive were removed from the curriculum and replaced by "legitimate" trade names.
    It's not rocket science but like all hobbies it take time to learn.
    Hope this helps
    Cheers
    Stephen
     
    Fid, SBSVC and kyratango like this.
  9. kingcake

    kingcake Member

    I have 1 that is small and sits flat on a desk..It was a gift and seems accurate..it doesnt, i like that it can tell the difference between jade and other gemstones.. I reccomend the presidium tester..but i would not sell on this evaluation alone.
     
  10. Marko

    Marko Well-Known Member

    I got the big clunky model. I love mine.
     
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