GemCad Derived Rendering by Bob Keller

SRB Variation with 12 Fold Symmetry | |
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Angles for R.I. = 1.54 | 85 facets + 24 facets on girdle = 109 |

12-fold, mirror-image symmetry | 96 index |

L/W = 1.000 T/W = 0.603 T/L = 0.603 P/W = 0.450 C/W = 0.139 | H/W = (P+C)/W+0.02 = 0.609 P/H = 0.739 C/H = 0.228 |

Vol./W^3 = 0.203 | Brightness at 0 degrees tilt for R.I. = 1.54
COS = 62.8% ISO = 66.3% |

Pavilion | |||
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pb | 43.00 | 02-06-10-14-18-22-26-30-34-38-42-46- 50-54-58-62-66-70-74-78-82-86-90-94 | Cut to temporary center point |

g | 90.00 | 02-06-10-14-18-22-26-30-34-38-42-46- 50-54-58-62-66-70-74-78-82-86-90-94 | Cut to meet pb |

pm | 42.00 | 96-08-16-24-32-40-48-56-64-72-80-88 | Cut to meet pb,g |

Crown | |||

cb | 37.00 | 02-06-10-14-18-22-26-30-34-38-42-46- 50-54-58-62-66-70-74-78-82-86-90-94 | Cut to meet g - level girdle |

cm | 35.00 | 96-08-16-24-32-40-48-56-64-72-80-88 | Cut to meet cb,g |

s | 18.00 | 04-12-20-28-36-44-52-60-68-76-84-92 | Cut to meet cb,cm |

t | 0.00 | Table | Cut to meet s,cm |

This variation of the SRB increases the number of facets in each course by 50% by increasing the symmetry from 8 fold to 12 fold. Increasing the number of facets increases the scintillation and is a way of scaling up the SRB to work with larger stones. |