Summary
Any time you have a blocky piece of rough that’s not square enough for an emerald cut, try the Hayek cut. Named after the Nobel Laureate economist F. A. Hayek, this design was developed to fit a specific piece of beryl rough. However, you’ll find this cut very useful for faceting other types of gems, too.
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Gemstone Recommendations

Hayek cut - Beryl

Hayek-cut beryl

To the right, this beauty has a Barion-style pavilion, which accounts for its great brilliance.

In rough with light to medium colors, the Hayek cut will have outstanding optical performance. However, I would caution against using this design for darker rough material.

This is a fairly simple design to facet. Now that you have it in your repertoire, you should find multiple occasions to cut it for your customers.

Diagrams

Hayek Cut Instructions

  • Angles for R.I. = 1.56
  • 45 facets + 4 facets on girdle = 49
  • 96 index
  • L/W = 1.500 T/W = 1.066 T/L = 0.710
  • P/W = 0.807 C/W = 0.110
  • H/W = (P+C)/W+0.02 = 0.937
  • P/H = 0.862 C/H = 0.117
  • Vol./W^3 = 0.628

Pavilion

Step Angle Index Notes
1 43º 96-06-12-18-24-30-36-4248-54-60-66-72-78-84-90 Cut to temp center point (TCP)
2 90º 44-92 Meet with step 3 at edge from step 1
3 90º 24-72 See step 2
4 75.5º 24-72 Meet at 1-2-3
5 75.5º 44-92 Meet at 1-2-3
6 42º 09-57 Add the mains last
7 41.5º 45-93
8 41.4º 33-81
9 41º 21-69

Crown

Step Angle Index Notes
a 42º 04-52 Steps a to f meet at corners
b 42º 24-72
c 30.7º 25-73
d 31.5º 23-71
e 32.2º 05-53
f 31.4º 03-51
g 25º 04-52 Meet e-a-f
h 22.1º 24-72 Meet c-d-b
T 0º Table Meet h-d-e-g and g-f-c-h