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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.

Viewing 7 posts - 1 through 7 (of 7 total)
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  • #199194
    Profile photo of msalguero
    msalguero
    Participant

    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.

    #199216
    Profile photo of bears10
    bears10
    Participant

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

    #199217
    Profile photo of happyduck
    happyduck
    Participant

    next step is a.: specific gravity

    #199218
    Profile photo of harsono
    harsono
    Participant

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

    #199219
    Profile photo of mercedes310
    mercedes310
    Participant

    Option a) check specific gravity

    #199220
    Profile photo of azam
    azam
    Participant

    A)check specific gravity is next step.

    #199238
    Profile photo of sydp
    sydp
    Participant

    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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