Faceting Made Easy, Part 6: Gemstone Design Cuts


hand cranked faceting machine - gemstone design

Note: This is a six-part edited version of Trevor Hannam’s Faceting Made Easy, a general introduction to faceting and a guide for learning to cut a standard brilliant gem. Part 6 includes the gemstone design cuts section as well as the bibliography. The International Gem Society thanks Mr. Hannam for permission to post his work.

The Emerald Cut

The emerald cut is basically designed for medium to dark colored stones or those with a low refractive index (RI). Although the depth of this gemstone design will enhance lighter colored stones, it does nothing for brilliance or scintillation.

Angles shown are for quartz. The best gemstone proportion ratio is 1.5 to 1.

Pavilion

  1. 90° 96-48-24-72
  2. 63° 96-48-24-72
  3. 43° 96-48-24-72
  4. 53° 96-48-24-72
  5. 53° 12-36-60-84
  6. 63° 12-36-60-84
  7. 90° 12-36-60-84

Cut the midway and corner facets with a 1,200 lap. Polish in reverse order.

emerald cut pavilion - gemstone design

Crown

  1. 55° Girdle, Indices 96-48-24-72-12-36-60-84. (Cut these facets to establish a girdle height 5% that of finished gem height).
  2. 42° Mains, Indices 96-48-24-72-12-36-60-84
  3. 27° Stars, Indices 96-48-24-72-12-36-60-84

Polish in reverse order.

emerald cut crown - gemstone design

Table

Table (4), use 45° angle dop. Set it up parallel with the lap surface. Then, set angle to 90°. Cut and polish.

emerald cut table - gemstone design

Notes

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