Billy Bob's Square by Billy Bob Riley

Billy Bob's Square Planviews

GemCad Ray Traces for RI = 1.54
Random Model Cosine Model 59.6 ISO Model 68.8
GemCad Ray Traces for RI = 1.72
Random Model Cosine Model 65.4 ISO Model 77.4

Billy Bob's Square by Billy Bob Riley
Angles for R.I. = 1.5461 facets + 4 facets on girdle = 65
4-fold, mirror-image symmetry96 index
L/W = 1.000 T/W = 0.567 U/W = 0.567 P/W = 0.650 C/W = 0.180
Vol./W^3 = 0.385 Brightness at 0° tilt
RI = 1.54: COS = 59.6 ISO = 68.8
RI = 1.72: COS = 65.4 ISO = 77.4

Pavilion
g90.00°96-24-48-72Establish size
167.35°96-24-48-72Establish level lower girdle line
258.63°01-23-25-47-49-71-73-95Meet g.1.1.g
347.64°05-19-29-43-53-67-77-91Meet g.1.2
442.84°10-14-34-38-58-62-82-86Meet g.1.2.3
541.50°96-24-48-72Meet 2.3.3.2, culet
Crown
a44.00°96-24-48-72Match g, make level upper girdle line
b35.89°01-23-25-47-49-71-73-95Meet g.a.a.g
c28.00°04-20-28-44-52-68-76-92Meet g.a.b
d22.48°11-13-35-37-59-61-83-85Meet g.a.b.c
T0.00°TableMeet b.c.c.b, make level table

Download PDF format printer friendly cutting instructions: [ Download Icon Billy Bob's Square Printer Icon ]

Download the GemCad format design file: [ Download Icon billy_bobs_square.gem ]


Index of Gem Designs

Perfect Transfer Index

Table of Contents

Bob Keller