Hubcap: Faceting Design Diagram

Successful tips, details and guide on Faceting Designs. A Faceting Design Diagram by Jeff R. Graham that presents various cuts, this one is called "Hubcap".


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

Hubcap (TLINE25.JRG)
By Jeff R. Graham
Copyright 1995
75% Light Return
Angles for R.I. = 1.62
105 facets + 8 facets on girdle = 113
8-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.497 T/L = 0.497
P/W = 0.441 C/W = 0.176
H/W = (P+C)/W+0.02 = 0.637
P/H = 0.692 C/H = 0.276
Vol./W^3 = 0.205

Gram Book 1 - The table is about 50% and it helps a lot if you rough it in before cutting the C4 facets, because they meet. This design is nice in about any color, 1-8cts. The reflection is higher than the ray trace indicates. Cut in refractive index 1.62 to 2.14 (85.3%) with no changes.



Random - Cosine - ISO

Detailed faceting instructions by Jeff Graham available at The Rock Peddler

Jeff R. Graham

The late Jeff Graham was a prolific faceter, creator of many original faceting designs, and the author of several highly-regarded instructional faceting books such as Gram Faceting Designs.

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!