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