| Nightmare - designed by Carl Downey 1/98 alckytxn@flash.net | |
|---|---|
| Designed for Beginning to Intermediate Faceters | |
| Based on 19 main designs in 'Faceting the Easy Way' by Don Clark | |
| Angles for R.I. = 1.54 | 77 facets + 19 facets on girdle = 96 |
| 1-fold, mirror-image symmetry | 96 index |
| L/W = 1.001 T/W = 0.542 T/L = 0.541 | P/W = 0.446 C/W = 0.163 |
| H/W = (P+C)/W+0.02 = 0.629 | P/H = 0.709 C/H = 0.259 |
| Vol./W^3 = 0.218 | Brightness at 0 degrees tilt for quartz
COS = 83.6 ISO = 91.6 |
| Pavilion | |||
|---|---|---|---|
| 1 | 42.00 | 96-05-10-15-20-25-30-35-40-45-51-56-61-66-71-76-81-86-91 | Meet at perm. culet point |
| 2 | 90.00 | 96-05-10-15-20-25-30-35-40-45-51-56-61-66-71-76-81-86-91 | Establish girdle position and width |
| Crown | |||
| M | 36.04 | 96-05-10-15-20-25-30-35-40-45-51-56-61-66-71-76-81-86-91 | Level girdle |
| S1 | 35.00 | 02-03-07-08-12-13-17-18-22-23-27-28-32-33-37-38-42-43-
53-54-58-59-63-64-68-69-73-74-78-79-83-84-88-89-93-94 | Meet M-2-2-M (watch those indexes!) |
| S2 | 34.75 | 47-49 | Meet M-2-2-M |
| T | 00.00 | Table | Meet S1-S1...S1-S2-S1...etc. |
Having read about the potential brilliance gains when cutting stones with odd numbered main facets, I was pleased to discover in the book Modern Faceting the Easy Way by Don Clark, a way to use a 96 index gear to cut 19 main facets. Several of the designs in the book have helped me increase recovery in expensive rough but most have simple step facets on the crown.
A cut with a single tier of 19 main facets for the pavilion and a step faceted crown is very bright (due to 'decreased opportunities for light extinction' - I am told) but somewhat - uhm...shall we say wearisome - after 3-4 stones. I wanted to keep the pavilion but decided to 'busy up' the crown. A little tricky to get it through GemCad but worked out fairly well. I have cut a Dinnerbucket Creek garnet and a chrome tourmaline (which showed RED highlights!) both with somewhat lower pavilion angles. I feel CZ might be quite nice too, but suggest lower pavilion angles (say-37 degrees) for it as well. The design as listed here should work well with quartz, beryl, tourmaline, topaz, etc.
