Octoburst by Steve Corman

Octoburst - designed by Steve Corman networks1@home.com
Angles for R.I. = Angles for R.I. = 1.74 65 facets + 8 facets on girdle = 73
8-fold, mirror-image symmetry 96 index
L/W = 1.000 T/W = 0.507 T/L = 0.507 P/W = 0.446 C/W = 0.163
H/W = (P+C)/W+0.02 = 0.683 P/H = 0.701 C/H = 0.269
Vol./W^3 = 0.255 Brightness at 10 degrees tilt for RI = 1.74
COS = 71.7 ISO = 82.1

Pavilion
  90.00 96-12-24-36-48-60-72-84  
1 56.00 96-12-24-36-48-60-72-84 Cut to level girdle
2 42.00 06-18-30-42-54-66-78-90 Meet 1-girdle
3 40.00 04-08-16-20-28-32-40-44-52-56-64-68-76-80-88-92 Meet 1-2. Cuts very fast! Use slow speed or stationary lap.
Crown
a 40.00 96-12-24-36-48-60-72-84 Level girdle
b 35.08 03-09-15-21-27-33-39-45-51-57-63-69-75-81-87-93 Meet a-girdle
c 30.21 96-12-24-36-48-60-72-84 No meet. Cut to consistent depth.
  00.00 Table Meet points of b facets formed by c facets

I named this cut Octoburst after the the sunburst pattern in the pavilion.  It is very simple, 3 steps each for the crown & pavilion.  It has a small number of total facets but the finished stone has a lot of sparkle due to the placement of the small ones.  According to Gemframe, it has average ISO brightness of 82.1% over a 10 degree tilt (at RI = 1.74).

Note on crown step c:  The depth of this cut is not crucial.  The depth shown in the diagram gives a 50% table. A deeper c cut will enlarge the table, but doing this too much shrinks the b facets and decreases the sparkle of the stone.

Editor's note: If you are cutting quartz (RI = 1.54), you should increase the angles for P3 and P2 as the pavilion #3 facets are below the critial angle for quartz.


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