IGS Background
Tack - Reflector gem design

Tack – Reflector: Faceting Design Diagram


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

By Jeff R. Graham, updated on

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

Tack - Reflector gem design

Tack - Reflector (CHECK3.JRG)
By Jeff R. Graham
Copyright 2000
88.9% Light Return
Angles for R.I. = 1.62
37 facets + 8 facets on girdle = 45
4-fold, mirror-image symmetry
96 index
L/W = 1.000 T/W = 0.235 T/L = 0.235
P/W = 0.478 C/W = 0.206
H/W = (P+C)/W+0.02 = 0.704
P/H = 0.679 C/H = 0.293
Vol./W^3 = 0.300

Addition # 6 - This is a neat one, the flashes are a true check. Notice that the corners float, this is to help get yield if your rough is not just right. Cut the corners in as close as you can to the diagram. If you are a bit off it will not really change much. I designed this for a piece of light multi-colored Tourmaline.


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!