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GIA VS OGI Report Please Advise

Discussion in 'RockyTalky' started by curious rock, Apr 4, 2002.

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  1. curious rock
    Rough_Rock

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    by curious rock » Apr 4, 2002
    Why is there a difference between the GIA Cert info compared to the OGI Report. EX:

    OGI
    Diameter = 6.66 (6.64-6.67)
    Total Depth = 60.8 4.05 mm
    Table Size = 58.3
    Culet = 0.4%

    GIA:
    Diameter = 6.65 -6.68
    Total Depth = 60.3 4.02 mm
    Table Size = 58
    Culet = None

    Which one is accurate or the more reliable between the two? Should I based it on the GIA and Ignore the OGI? Why is there such an obvious discrepancies?
     
    


    


  2. oldminer
    Ideal_Rock
    Trade

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    by oldminer » Apr 4, 2002
    I think you might say they are the same considering the machine error allowed in the the Sarin and the Ogi. The nuymbers are really very similar so no one can tell you which, if either, is more correct.

    Take 10 readings on each machine and let the most common set of results indicate the most probable correct actual numbers. One measurement taken on each is not going to have statistical validity.
     
  3. curious rock
    Rough_Rock

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    by curious rock » Apr 4, 2002
    Hi,

    f there not much difference between the two reports, how come that the HCA is giving to different reading using these two parameters? Based on OGI Report, the HCA is 2.4, Light Return & Spread = Very Good, Fire & Scintillation = Good. Using the GIA having the same Crown and Pavillion Angle but different Depth, Table nd Culet, the HCA is 2.2, Light Return = Very Good, Spread = Excellent, Fire = Very Good & Scintillation = Good.
    Obviuously based on the HCA, there is quite a big diiference between the two reports.

    Thanks for your expert opinion
     
  4. Garry H (Cut Nut)
    Super_Ideal_Rock
    Trade

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    by Garry H (Cut Nut) » Apr 4, 2002
    Input different #'s and you get different output.

    There are some very critical zones where small changes in #'s give largish variations in performance.
     
    


    


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