Faceting Design Diagram: Snowflake – Tourmaline – Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite


Tourmaline (Achroite, Dravite, Rubellite, Indicolite, Verdelite, Siberite)

Snowflake (TLINE13.JRG)
By Jeff R. Graham
Copyright 1993
75.9% Light Return
Angles for R.I. = 1.62
169 facets + 16 facets on girdle = 185
8-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.440 T/L = 0.440
P/W = 0.441 C/W = 0.172
H/W = (P+C)/W+0.02 = 0.633
P/H = 0.697 C/H = 0.272
Vol./W^3 = 0.218

Addition # 1 – This design makes a nice stone in light material and because of the number of facets I cut it in a large size. It’s reflection is higher than it ray traces and takes some work to cut. Cut in refractive indexes 1.62 to 1.93 (89.1%) with no changes.


Random – Cosine – ISO

Detailed faceting instructions by Jeff Graham available at The Rock Peddler

Gram Faceting Archive of Information
This edited version of an article by the late Jeff Graham is part of a special archived informational series from Gram Faceting. Used with permission.