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

Gram Barion Pear (B42.JRG)
By Jeff R. Graham
Copyright 2001
86.2% Light Return
Angles for R.I. = 1.62
74 facets + 16 facets on girdle = 90
1-fold, mirror-image symmetry
96 index
L/W = 1.436 T/W = 0.677 T/L = 0.472
P/W = 0.624 C/W = 0.185
H/W = (P+C)/W+0.02 = 0.829
P/H = 0.753 C/H = 0.223
Vol./W^3 = 0.432

Addition # 5 – A lot of people have asked me for a Barion pear that performs well. Here it is… Cut in R.I. 1.62 to 1.93 (87.0%) with no changes. I recommend large and light materials for this design. The breaks are steep, set it from the ends. Notice the P21 & P22 do not meet breaks, these absorb any slack in case your L/W is off a bit. P22 can be fudged to meet breaks… I fudge.


Random – Cosine – ISO

Detailed faceting instructions by Jeff Graham available at The Rock Peddler