Forums General Discussion Master Class Single Stone

  • Master Class Single Stone

    Posted by Ronald A Maitland on January 2, 2021 at 12:55 pm

    Looking at the diagram for the master class single stone competition, several index settings are in decimal numbers. I have never seen this before. Does one round up/down, or use the cheater?

    Ron Maitland

    Alan Balmer replied 3 years, 6 months ago 4 Members · 6 Replies
  • 6 Replies
  • master1975

    January 2, 2021 at 2:40 pm

    The pavilion and crown angles are listed to the hundredth of a degree. The index settings are whole numbers.

  • Dennis Anderson in sunny Southern California

    January 2, 2021 at 3:11 pm

    It is normal for the designs in the SSC to have angles listed in decimal to two decimal places. This is a result of the computer designs having this capability. You are expected to interpolate on your faceting machine to best approach this angle and cut all the facets in a tier to that consistent angle. If you do this well, the result will be a stone that will be judged based on the parameters in the judging manual. There is no means for the judge to measure angles to 1/100ths of a degree.

  • Ronald A Maitland

    January 2, 2021 at 4:45 pm

    The crown tier C facets show indexes in decimal tenths.


  • Ronald A Maitland

    January 2, 2021 at 5:15 pm

    For anyone cutting this stone, I figure the correct C indexes to be; 5-19-29-43-53-67-77-92.


  • Ronald A Maitland

    January 2, 2021 at 5:16 pm

    Sorry. Last index should be 91.


  • Alan Balmer

    January 4, 2021 at 11:37 am

    Hi, Ron. There seems to be a discrepancy between the design in the newsletter and the one on the website. I think the website version is correct (no fractional indexes). Click on “Competition” in the menu. No login required.

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