IGS Background

Crown Star: 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 "Crown Star".

By Jeff R. Graham, updated on

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

Crown Star (CHECK14.JRG)Chrysoberyl cut by Tony Carson
By Jeff R. Graham
Copyright 2001
88% Light Return
Angles for R.I. = 1.62
53 facets + 12 facets on girdle = 65
4-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.373 T/L = 0.373
P/W = 0.442 C/W = 0.180
H/W = (P+C)/W+0.02 = 0.642
P/H = 0.688 C/H = 0.281
Vol./W^3 = 0.259

Addition # 6 - Cut this in refractive indexes 1.62 to 1.92 with no changes. This makes a very bright and sparkly stone. Notice that the pavilion facets P5, P6 are creating a lot of movement.


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!