The Gemstone Butterfly Cut

The Butterfly Cut
The Butterfly Cut

The Butterfly Cut gemstone design goes together simply, and the results are stunning. There are only a few comments to make. Obviously, the larger the gem, the more visible your butterfly will be. This has been cut as small as 8 mm, but 10 mm and up is preferred. This was originally designed with 42º pavilion mains. Even though a majority of the pavilion is cut at this angle, it has very little brilliance. In this variation, it has been made thinner, as if you were going to cut it in garnet or some other dark material. Here, the emphasis is on the design, not brilliance. It can be converted back to 42º mains, or made thinner to accommodate your rough. Use the “keep your distance” rule” and add or subtract the same amount to each setting.

The Butterfly Cut: A Step-By-Step Guide

Step Angle Index
1 90º 02-07-11-16-21-25-30-34-39-43-48-53-57-62-66-71-75-80-85-89-94
2 45º 02-07-11-16-21-25-30-34-39-43-48-53-57-62-66-71-75-80-85-89-94
3 35º 02-07-11-16-21-25-30-34-39-43-48-53-57-62-66-71-75-80-85-89-94
4 32º 37-59
5 32º 30-66
6 32º 16-21-26-70-75-80
7 33.4º 09-87
8 33.8º 96
9 34.2º 46-50
  1. Create girdle.
  2. Girdle facets.
  3. Leave frosted. These facets outline the design and also determine how far in the edge of the wings are.
  4. The first wing facets are cut to the edge of the 45º facets in step 2.
  5. The remaining wing facets are cut to the outer edge of the previous wing facet. They will not meet perfectly in the center.
  6. The remaining wing facets are cut to the outer edge of the previous wing facet. They will not meet perfectly in the center.
  7. The remaining wing facets are cut to the outer edge of the previous wing facet. They will not meet perfectly in the center.
  8. This is the abdomen. Cut on the pre-polish lap and position by eye.
  9. The antennae are very tiny. Cut on the polishing lap!

Butterfly Cut Techniques

The butterfly is highlighted by leaving the surrounding facets frosted. While that may seem pretty straightforward, there is a trick to the technique. Essentially, you want to bring them down to as fine a finish as possible without taking them to a semi-polished look. This can usually be accomplished with a 1,200 lap, but you may need to use a 600 in some cases. Why should you avoid the semi-polished look? Because once you reach the polishing stage, if you try to polish next to a much rougher surface, like a 360, small bits of the rough will break off and scratch your facets. Worse yet, they could get embedded in your polishing lap!

You’ll notice I haven’t listed any crown settings. In the diagram below, the crown is step-cut with two rows of facets cut at 35º and 25º, using the index setting in step 1. In a design like this, leaving the table as large as the interior design is usually desirable. That isn’’t a high priority in this case. I have cut these with the crown facets overlapping the wing tips and the results are not only satisfactory but also quite pleasant.

The Butterfly Cut - Three Views
The Butterfly Cut – Three Views

If you have the skill, try to cut a domed crown with cabbing equipment. Remember, the thinner the crown, the more the butterfly will be magnified.

About the author
Donald Clark, CSM IMG
Donald Clark, CSM founded the International Gem Society in 1998. Donald started in the gem and jewelry industry in 1976. He received his formal gemology training from the Gemological Institute of America (GIA) and the American Society of Gemcutters (ASG). The letters "CSM" after his name stood for Certified Supreme Master Gemcutter, a designation of Wykoff's ASG which has often been referred to as the doctorate of gem cutting. The American Society of Gemcutters only had 54 people reach this level. Along with dozens of articles for leading trade magazines, Donald authored the book "Modern Faceting, the Easy Way."
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