| The 'Freeborn' John (Lilburne) by Carl R. Downey, alckytxn@flash.net 5-2-96 | |
|---|---|
| Named for a guy that influenced our Founding Fathers | |
| Angles for R.I. = 1.62 (Topaz) | 61 facets + 6 facets on girdle = 67 |
| 2-fold, mirror-image symmetry | 96 index |
| L/W = 1.466 T/W = 1.014 T/L = 0.692 | P/W = 0.681 C/W = 0.128 |
| H/W = (P+C)/W+0.02 = 0.829 | P/H = 0.821 C/H = 0.154 |
| Vol./W^3 = 0.421 | |
| Pavilion | |||
|---|---|---|---|
| 1 | 42.50 | 02-06-10-14-18-22-26-30-34-38-42-46-
50-54-58-62-66-70-74-78-82-86-90-94 | cut to temporary culet |
| 2 | 90.00 | 24-72 | Cut to meet edge from culet as shown |
| 3 | 90.00 | 06-42-54-90 | Meet 1 & 2 to complete outline |
| 4 | 72.29 | 24-72 | Meet at corners - CAREFULLY! |
| 5 | 72.29 | 06-42-54-90 | Meet 1,2,3,4 at corners |
| 6 | 41.50 | 08-40-56-88 | Add... |
| 7 | 41.62 | 96-48 | ...the... |
| 8 | 41.81 | 16-32-64-80 | ...Mains... |
| 9 | 42.00 | 24-72 | ...Last |
| The step 5 facets will require a lot of time polishing | |||
| On small stones try 41.7 for ALL pavilion mains | |||
| Crown | |||
|---|---|---|---|
| a | 38.00 | 06-42-54-90 | Meet corners, establish girdle |
| b | 28.26 | 03-45-51-93 | Meet a-a, 3-3 |
| c | 28.26 | 09-39-57-87 | Meet a-2-3 |
| d | 28.26 | 23-25-71-73 | Carefully meet a-c-2-3 (polish last) |
| e | 29.55 | 24-72 | Complete girdle |
| T | 00.00 | Table | Cut to a-b-c |
| On small stones try deleting 'd' and cut 'e' @ 28.26 | |||
Well, I wish I could say that the idea for the 'Freeborn ' John (Lilburne) cut was inspired by a shape that I saw somewhere, something I had read or a 'vision'. It was born out of a mind full of frustrated rage! I owned a small 'champagne' colored topaz whose shape seemed to require a marquis. But I hate marquis cuts! The gauntlet was down! No mere mineral was going to get the best of this animal!
So, I looked at some ovals, but I had just finished a Barion oval (highly recommended) and wanted to do something different. Well, Mr. Strickland's GemCad was no longer a mystery to me (although I still have not yet trained myself on ALL the shortcuts/features) having entered, corrected, altered and 'angle translated' printed cuts from 3-4 sources.
Feeling somewhat lazy I thought of a shape with as few sides as possible but WITHOUT marquis-type 'pointy' ends. An 'oblong hex' (elongated or stretched might be a better term - now I think of it!) came to mind. The best place to start most designs is the most critical feature: the pavilion. Sometimes, designing gemcuts is done 'backwards and sideways' compared to the final cutting sequence.
Mentally overlaying an oblong hex on a series of 'break facets' indicated the 'corners' as useful meetpoints. This would make it a little easier to use the stone as a guide during cutting instead of trying to take measurements. Next was 'marrying' the outline to the pavilion. BARION type facets did the trick. (later, while trying to polish a stone with - effectively - FIVE TABLES, I'd realize a convenient construction element would mean slow cutting!). A simple 'cardinal cut' table looks a little better than step cuts but I have used both.
Also, the pavilion mains could be deleted but I prefer them. This general technique/cut can be used with other indexes. (I've designed one for the 80). The tiny barion-type facets on the ends could easily be deleted. Since I'm writing this primarily for other GemCad users, by running this cut through GemRay you will find appropriate positions for 4 symmetrically located jewelry prongs at some 'dark spots' about 1/3 in from the ends! I wish I could say I designed it that way! ;-)
Happy Cutting!
