Faceting Design Diagram: Delta “T” – Peridot – Olivine, Green, apple green to yellow green


Peridot (Olivine, Green, apple green to yellow green)

Delta “T” (PDOT8.JRG)
By Jeff R. Graham
Copyright 1998
76% Light Return
Angles for R.I. = 1.67
34 facets + 9 facets on girdle = 43
3-fold, mirror-image symmetry
96 index
L/W = 1.053 T/W = 0.611 T/L = 0.580
P/W = 0.487 C/W = 0.223
H/W = (P+C)/W+0.02 = 0.730
P/H = 0.668 C/H = 0.305
Vol./W^3 = 0.249

Addition # 3 – The P3 cuts to center point, when they look like long straight sided rectangles(3) they are right. You may have to fish a little. The rest of this design cuts easy, any material, 1-8cts. Cut in refractive indexes 1.67 to 2.14 (78.6%)with no changes.


Random – Cosine – ISO

Detailed faceting instructions by Jeff Graham available at The Rock Peddler

About the author
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.
All articles by this author