More faceting questions from the Mail Bag:
I am faceting an Aquamarine with optimized angles using your Catamaran design from 2003. However, using GemRay to optimize the angles for the best figure or Merit, the weight fraction gets reduced from .663 to .488 which is a large loss in yield. Neglecting the issue of yield, I have been maximizing the "Merit" scores of GemRay and have noticed that figure is highly dependent on the brightness weights, which all default to 1.0. Having very little experience with what makes a more beautiful stone, I have been leaving the brightness weights all at 1.0 when optimizing angles (see attachment). However, I wonder if higher figures of merit really result in a noticeable improvement in beauty. Given that some optimized scores may reduce yield by as much as 30%, I was wondering if you may have some pointers regarding setting those brightness weights for better looking results, without an unnecessary loss in yield. Do you have suggestions regarding the best way to select better angles for the various stone types Jim
Hi, Jim,
Thanks for the note.
I just commented on a thread on FaceBook today about this very thing – attention to the numbers in GemRay, and thinking that optimizing faceting angles by those numbers will optimize the beauty and/or value of a gem.
The short answer to your question is another question:
“How can we best optimize the COLOR of the gem in question?”
It’s important to keep in mind that color accounts for 60% or more of value in colored stones. So, rather than focusing on light return, we may want to focus on presentation of color. Then, we can consider our manipulation of light return through intentional use of design features – to influence color to best effect – which, in a lighter gem like Aquamarine may have us desiring to return less light rather than more.
Note that generally, the more light we return, the more we wash-out the apparent saturation of the gem.
My suggestions regarding “selecting better angles for various stone types” – is to give up thinking about the issue by generalizing by species or RI and “best angles”. I think it’s better to think about it based on the color quality of the individual gem – and how to best present the color of that stone, considering the RI as just one of the many characteristics of that individual stone – like how it may be included, how it’s shaped, etc.
I realize that this may not be the pat answer you were looking for – and that what this really does is broaden the puzzle. That’s what it does for me – and that’s the way I like it: Every stone as an individual creative puzzle and expression. Otherwise, faceting could become just assembly-line-like work.
Hope this opens doors to thinking that enhances your enjoyment and exploration of faceting – and that you enjoy the adventures to be found there.