A Guide to Gem Cutting Styles
by Donald Clark, CSM IMG, Phoebe Shang, GG
Step 1: Introduction to Gemology
Lesson 23
Summary
While some cut names may describe the face-up shape of the finished gem, others refer to the shape and arrangement of the gem’s facets. These cuts are also known as gem cutting styles. The three most basic cutting styles are brilliant, step, and mixed. For example, a “round brilliant diamond” has a round shape but a brilliant cutting style. Faceters can combine these styles to create many different gem designs.
Reading time: 9 min 36 sec
A trilliant-cut smoky quartz, 8.92 cts, 14.05 x 14.05 x 8.69mm. Gem cutting and photo by Peter Torraca. Used with permission.
(1) Round brilliant, top view (2) Oval brilliant, top view (3) Rose cut, top view (4) Round brilliant, side view (5) Cushion brilliant, top view (6) Rose cut, side view (7) Step cut, octagon (8) Pear brilliant, top view (9) Step cut, oblong (10) High cabochon, side view (11) Cabochon, side view (12) Lentil-shaped, side view. Gemstone Cuts. No known copyright restrictions.
"The Three Basic Gem Cutting Styles
Brilliant Cut
Brilliant cuts consist of triangular and kite-shaped facets that spread outward from the center of the gem. As befits its name, the brilliant cut gives off the most scintillation of any cut.
Round brilliant facet chart. Image by Jasper Paulsen. Licensed under CC By-SA 3.0.
Step Cut
Step cuts consist of rectangular facets that ascend the crown and descend the pavilion in steps. Examples of step cuts include emerald and baguette cuts. These are popular because they show off the stone’s color and clarity and produce a subtle gleam.
Emerald cut. Image by Ducky. Licensed under CC By-SA 3.0.
Mixed Cuts
Mixed cuts combine step cut and brilliant cut styles. They have brilliant facets on the crown and step facets on the pavilion, or vice versa. Mixed cuts may even combine cabbing and faceting techniques.
Mixed-cut oval citrine. Photo by Wela49. Licensed under CC By-SA 3.0.
Shape and Style Combinations
Faceters can combine the above cutting styles with almost any shape. For example, a square modified brilliant is a princess cut. A square step cut with beveled corners is an Asscher cut. A square mixed cut is a Barion cut.
Step and mixed cuts apply to fancy shapes only. No step-cut or mixed-cut rounds exist.
Of course, you can also find variations within all shapes. A triangular gem can have many or few facets, much or little brilliance and scintillation, etc.
Rose Cut
While brilliant and step cuts currently enjoy the most popularity, the rose cut is a unique style important to gem-cutting history. Dating back to the 16th century, the rose cut has a round, cabbed flat base and a faceted top. (Occasionally, you’ll see a gem with a faceted pavilion and a domed crown. However, this isn’t a standard cutting method).
Rose cut
Triangular facets rise to form a shape like a faceted mound. While the number of facets on each rose cut varies, the face-up shape is almost always circular. For 16th-century cutters, roses maximized the use of flat rough and created gems with more brilliance than previously seen.
Rose cut facet chart. Fig. 157-160 round rose, 161 oval rose, 162 drop rose, 164 side view of rose. No known copyright restrictions.
However, this cut ... "
https://www.gemsociety.org/article/gem-cutting-terms/