Hexidec
| GemCad Ray Traces for RI = 1.54 | ||
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| Random Model | Cosine Model | ISO Model |
| Hexidec – Designed by Paul A. Head headbnk@azstarnet.com ©1995 | |
|---|---|
| Angles for R.I. = 1.54 | 129 facets + 16 facets on girdle = 145 |
| 16-fold, mirror-image symmetry | 96 index |
| L/W = 1.000 T/W = 0.503 T/L = 0.503 P/W = 0.450 C/W = 0.146 | H/W = (P+C)/W+0.02 = 0.616 P/H = 0.731 C/H = 0.236 |
| Vol./W^3 = 0.201 | Brightness at 0 degrees tilt for quartz Cos = 86.0% ISO = 91.5% |
| Pavilion | |||
|---|---|---|---|
| P1 | 42.00 | 01-05-07-11-13-17-19-23-25-29-31-35-37-41-43-47-49-53-55-59-61-65-67-71-73-77-79-83-85-89-91-95 | Cut to Common Center Point |
| G1 | 90.00 | 96-06-12-18-24-30-36-42-48-54-60-66-72-78-84-90 | Set width of stone. |
| P2 | 43.00 | 96-06-12-18-24-30-36-42-48-54-60-66-72-78-84-90 | Meet G1-G1-P1;makes level Girdle. |
| P3 | 41.50 | 96-06-12-18-24-30-36-42-48-54-60-66-72-78-84-90 | Meet P1-P1-P2,forms new CCP. |
| Crown | |||
| C1 | 31.00 | 96-06-12-18-24-30-36-42-48-54-60-66-72-78-84-90 | Match G1; Leave 2% of W for girdle. |
| C2 | 30.1 | 01-05-07-11-13-17-19-23-25-29-31-35-37-41-43-47-49-53-55-59-61-65-67-71-73-77-79-83-85-89-91-95 | Meet G1-G1-C1 at Girdle. |
| C3 | 29.00 | 96-06-12-18-24-30-36-42-48-54-60-66-72-78-84-90 | Meet C1-C2-C2 |
| 0.00 | Table | Meet C2-C2-C3-C3 | |
I have cut a 22.8 mm topaz from this design with no difficulty but would not want to try a 10 mm size. Note that the angles shown are not given for any particular R.I. – you will need to tangent ratio them as appropriate for the R.I. of the material you select. This design is both simple and easy to cut.
| Recommended Hexidec Angles for Other Refractive Indexes | ||||
| R.I. = 1.62 P1 40.5 P2 41.5 P3 40.0 C1 32.0 C2 31.1 C3 30.0 P/W = 42.7% C/W = 15.1% ISO = 92.2% |
R.I. = 1.76 P1 41.0 P2 42.0 P3 40.5 C1 42.0 C2 41.0 C3 39.7 P/W = 43.5% C/W = 21.8% ISO = 90.2% |
R.I = 1.76 P1 36.5 P2 37.4 P3 36.0 C1 41.0 C2 40.0 C3 38.7 P/W = 37.0% C/W = 21.0% ISO = 87.6% |
R.I. = 2.15 P1 32.5 P2 33.4 P3 32.0 C1 44.0 C2 43.0 C3 41.7 P/W = 31.8% C/W = 23.4% ISO = 94.8% |
R.I = 2.15 P1 42.0 P2 43.0 P3 41.5 C1 37.0 C2 36.0 C3 34.8 P/W = 45.1% C/W = 18.2% ISO = 92.0% |
The dual choices for R.I. 176 and 2.15 are because the ISO brightness contour maps have two high value ridges. I have not picked the absolute highest ISO values but have hedged toward higher crowns to enhance the effects of dispersion.
Enjoy cutting your Hexidec!
GemCad File