IGS Background

Odd Round n’ Round: Faceting Design Diagram


Successful Tips and guide on Faceting Designs. Faceting Design Diagram by Jeff R. Graham that presents various cuts, this one is called "Odd Round n' Round"

By Jeff R. Graham, updated on

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

Odd Round n' Round (TLINE1.JRG)
By Jeff R. Graham
Copyright 1993
83.4% Light Return
Angles for R.I. = 1.62
129 facets + 16 facets on girdle = 145
8-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.489 T/L = 0.489
P/W = 0.426 C/W = 0.157
H/W = (P+C)/W+0.02 = 0.603
P/H = 0.707 C/H = 0.260
Vol./W^3 = 0.217

Addition # 2 - This design is for light to med material, 1-16cts. It has a nice uneven sparkle in every direction and is fun to cut because of it's odd symmetry. Cut in refractive indexes 1.54 to 2.14 (91.4%) with no changes.


Random - Cosine - ISO

Detailed faceting instructions by Jeff Graham available at The Rock Peddler

Never Stop Learning

When you join the IGS community, you get trusted diamond & gemstone information when you need it.

Become a Member

Get Gemology Insights

Get started with the International Gem Society’s free guide to gemstone identification. Join our weekly newsletter & get a free copy of the Gem ID Checklist!