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August 1 eNews Mini-Quiz Question

This topic contains 6 replies, has 7 voices, and was last updated by Profile photo of sydp sydp 1 year, 1 month ago.

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    Profile photo of msalguero

    You are examining a transparent, faceted blue gem. You measured the RI as 1.633 to 1.638 and found the optic sign is uniaxial. What should you do next?
    a) check specific gravity
    b) check UV
    c) check pleochroism.

    Profile photo of bears10

    The RI is between Tourmaline and Peridote so I would do (a) SG.

    Profile photo of happyduck

    next step is a.: specific gravity

    Profile photo of harsono

    Check for pleochroism because the possibilities are Topaz (blue) or Paraiba Tourmaline or Indicolite.

    Profile photo of mercedes310

    Option a) check specific gravity

    Profile photo of azam

    A)check specific gravity is next step.

    Profile photo of sydp

    personally would have used a polariscope first then maybe the refractometer.
    I then would have used a spectroscope to see if I could get a spectrum. even may have used this after the polariscope
    I would think that with the RI and the Birefringence that you have said, if it were uniaxial negative that the gem would be apatite and I should get a good didymium spectrum.
    No need to check specific gravity if that were the case as the spectrum would be diagnostic
    please make comment if you wish thanks

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