is a rejection tool to help you narrow your search for only round diamonds potential Light Return, Fire, Scintillation and Spread based on the rounded proportion information from a grading report.
(HCA was upgraded April 2019 to include ‘Looks Like’ diamond size enabling a bonus or penalty for symmetry. Looks Like is also more accurate than the old ‘Spread’ in HCA).
Looks Like(Patent Pending) additionally uses carat weight, dimensions and symmetry to calculate the spread for carat weight and estimate the peripheral or edge leakage to arrive at an estimated apparent size for the given weight.
Scores of 0-1 are usually not best for rings. Most people prefer stones that score 1-2, or even top Hearts & Arrows symmetry stones up to 3.0. Zero is almost impossible since many performance factors conflict.
Crown % and Pavilion %'s are less accurate than angles.
Good luck finding a sparkly diamond. Garry Holloway FGAA, Dip diamond Technology.