Classic I gem designClassic I gem design

Classic I: Faceting Design Diagram

Detailed information and guide on Faceting Designs. A Faceting Design Diagram by Jeff R. Graham that presents various cuts, this one is called "Classic I".


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

Classic I gem design

Classic I (MC26.JRG)
By Jeff R. Graham
Copyright 1999
88.6% Light Return
Angles for R.I. = 1.62
49 facets + 12 facets on girdle = 61
4-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.558 T/L = 0.558
P/W = 0.442 C/W = 0.164
H/W = (P+C)/W+0.02 = 0.626
P/H = 0.706 C/H = 0.262
Vol./W^3 = 0.252

Addition # 4 - This is one of my favorites to cut, it is fast and easy. Also this is such a classic shape most jewelers love to use it, and more important buy it. It works in any decent rough, 1cts+. Cut this in R.I. 1.62 to 2.14 (87%) without 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!