| GemCad Ray Traces for RI = 1.62 | ||
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| Random Model | Cosine Model | ISO Model |
| PentaRound
Designed by Bob Keller - November 2001 Bob Keller |
|
| For Topaz, Tourmaline, Garnet, Spinel, Corundum | |
| Angles for R.I. = 1.62 | 56 facets + 20 facets on girdle = 76 |
| 5-fold, mirror-image symmetry | 120 index |
| L/W = 1.000 T/W = 0.553 T/L = 0.553 P/W = 0.429 C/W = 0.174 | H/W = (P+C)/W+0.02 = 0.623 P/H = 0.689 C/H = 0.279 |
| Vol./W^3 = 0.204 | Brightness at 0 degrees tilt for RI = 1.62 COS = 80.8 ISO = 88.7 |
| Pavilion | |||
|---|---|---|---|
| 1 | 41.00 | 003-009-015-021-027-033-039-045-051-057 063-069-075-081-087-093-099-105-111-117 | Cut to centerpoint - make culet |
| g1 | 90.00 | 003-009-015-021-027-033-039-045-051-057 063-069-075-081-087-093-099-105-111-117 | Match 1 - make level girdle |
| Crown | |||
| a | 36.47 | 003-021-027-045-051-069-075-093-099-117 | Match g1, establish upper gridle line |
| b | 40.00 | 009-015-033-039-057-063-081-087-105-111 | Match g1.a.g1 |
| c | 35.26 | 002-022-026-046-050-070-074-094-098-118 | Meet a.g1.g1.a |
| d | 31.01 | 120-024-048-072-096 | Meet c.a.b |
| t | 0.00 | Table | Meet d.c.a.b |
A PentaRound Design File is available for GemCad users.
