The Holloway Cut Adviser (U.S. Patent 7,251,619) estimates a round diamonds appeal based on its potential Light Return, Fire, Scintillation and Spread.
Most people prefer stones that rate 1-2 on a scale where: 0-2 Excellent, 2-4 Very Good, 4-6 Good, 6-8 Fair, and 8-10 Poor. Zero is almost impossible since many of the factors conflict.
You need Total Depth %, Table % and Crown° and Pavilion° angles from AGS and 2006 GIA and IGI reports. Some reports list less accurate rounded Crown % and Pavilion %’s; run the stone and if it scores under 2.0, ask the vendor to get you a Helium, Sarin or Ogi report with angles.
HCA gets no info on symmetry, polish and minor facets; use it only to reject likely bad performing diamonds to narrow down your final selection. Ideal-Scope images and independent appraisers can help after that.
The tutorial explains more about Cut and diamond beauty. A detailed description of HCA is available at www.diamond-cut.com.au. |
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