| The Trouble With Tribbles | |
|---|---|
| Adapted from Tribble by Robert W. Strickland | |
| Copyright 9/18/94 by J. Rowland | |
| Angles for R.I. = 1.54 | 61 facets + 15 facets on girdle = 76 |
| 3-fold, mirror-image symmetry | 96 index |
| L/W = 1.032 T/W = 0.516 T/L = 0.500 | P/W = 0.430 C/W = 0.162 |
| H/W = (P+C)/W+0.02 = 0.661 | P/H = 0.703 C/H = 0.264 |
| Vol./W^3 = 0.197 | |
| Pavilion | |||
|---|---|---|---|
| 1 | 46.00 | 14-18-46-50-78-82 | Cut to TCP |
| 2 | 43.00 | 10-22-42-54-74-86 | Meet TCP of 1 |
| 3 | 90.00 | 14-18-46-50-78-82 | Cut to final size |
| 4 | 90.00 | 10-22-42-54-74-86 | Meet 1-2-3 (level girdle) |
| 5 | 44.50 | 16-48-80 | Meet 1-1-3-3 |
| 6 | 42.96 | 12-20-44-52-76-84 | Adjust to meet culet and 2-3-4 |
| 7 | 42.10 | 09-23-41-55-73-87 | Meet 2-2-6-6. Sensitive to angle! |
| 8 | 47.00 | 96-32-64 | Meet 2-7-4 |
| 9 | 90.00 | 96-32-64 | Meet 2-7-4-8 |
| Crown | |||
|---|---|---|---|
| A | 45.50 | 14-18-46-50-78-82 | Leave some girdle |
| B | 38.00 | 10-22-42-54-74-86 | Level girdle |
| C | 42.00 | 16-48-80 | Cut to girdle meet |
| D | 29.00 | 08-24-40-56-72-88 | Cut to A-B-C meet |
| E | 54.00 | 96-32-64 | Level girdle and make B-D meet |
| S | 20.00 | 08-24-40-56-72-88 | Cut to A-B-C-D meet |
| T | 00.00 | Table | Cut table to S-C meets |
| Really Good for Low RI Material Light in Color | |||
| Don't try this cut under about 10 mm | |||
| I Cut an 18 mm White Topaz and It's Not Too Big! | |||
This month's cut is called "The Trouble With Tribbles". It seems that I tried to cut a design
called "Tribble" that came with my GemCad program. The table of Tribble required me to hit 6
meet points at the same time and it just wouldn't work. The stone's design also did not lend
itself to cutting the table other than last.
I had trouble with Tribble, thus the name of the fix. I lowered the center main facets and added
a set of star facets and ended up with a table with only 3 meet points - the perfect number. You
can ALWAYS make 3 meets. Anything more is iffy depending on your machine.
"Trouble" Photo Courtesy Martin Friedlander
I cut "The Trouble With Tribbles" from a large water-worn topaz pebble and ended up with an 18 mm 20 carat beauty. This cut would go much bigger and continue to be breathtaking. Use it for stones 10 mm and larger. It works great with low RI material such as quartz and topaz.
The pavilion is cut to a Temporary Center Point (TCP). Don't worry about the loss of material due to this approach. There is almost no change in depth but without it the proportions don't work out.
