A Guide to Gem Cutting Styles


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
gem cutting styles - trilliant cut
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.
gem cutting styles - gem cut chart
(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.

gem cutting styles - round brilliant facet chart
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.

gem cutting styles - emerald cut
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.

gem cutting styles - mixed-cut citrine
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 - gem cutting styles
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.

gen cutting styles - rose cut facet chart
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 gives little fire. It’s not nearly as bright as a modern brilliant. Over subsequent centuries, many jewelry owners had their rose-cut diamonds recut into more fashionable shapes. Of course, fashions do turn. Rose cuts are now making a comeback due to their vintage appeal.

gem cutting styles - rose-cut diamond earrings
Ear climbers in 18K yellow gold with rose-cut diamonds (approx. 3.23-ctw) and white brilliant-cut diamonds (approx. 0.20-ctw). Photo courtesy of Todd Reed, Inc.

Briolette Cut

Another notable vintage cut, the briolette is a faceted teardrop. It also resembles a fully rounded pear or a double-rose cut. During Victorian times, jewelers often drilled these then-popular gems to use as beads for pendants and earrings.

gem cutting styles - briolette cut
1900s topaz and diamond necklace with topaz briolette pendant. Photo by Naomi King. Licensed under CC By 2.0.

Ceylon Cut

The Ceylon cut has a step-cut pavilion and a brilliant-cut crown. This ancient technique is still used in Sri Lanka. Studies have shown that the reverse, a step-cut crown over a brilliant-cut pavilion, will often produce the greatest brilliance.

Barion Cut

While a mixed cut, the Barion cut also deserves a category of its own. Essentially, it places a round brilliant pavilion into a fancy shaped gem. It usually has a step-cut crown as well. This typically results in far greater brilliance than other methods. However, Barion cuts can come in almost any shape and vary widely in their facet arrangements.

A commercially cut, triangle-cut green zircon is recut into a custom Barion triangle by Peter Torraca. Barion cut and before and after photos by Peter Torraca. Used with permission.

Some have brilliant facets on both crown and pavilion, while others have step cuts on the crown and brilliant cuts on the pavilion. Their unifying feature, which separates the Barion from mixed cuts, is the quarter moon facets located directly beneath its girdle.

The arrangement of Barion-cut facets also creates a characteristic cross-shaped pattern at the center of the stone. Barions eliminate the bowtie extinction effect. Also, since they tend to be deeper than other cuts, they allow cutters to maximize rough and concentrate on color.

Barions with round brilliant pavilions, compared to other pavilion shapes, offer greater light discipline inside the gem. Such a gem can display a striking “fountain of light” effect.

gem cutting styles - Barion cut facets

Modified Cuts

Gem cutters can modify brilliant, step, and rose cuts to maximize use of rough or create interesting effects. The shape and facet types remain the same, but the number and arrangement of facets may differ.

If cut differently from the standard, gems have the term “modified” added to their names. For example, “modified round brilliant” or “modified emerald cut.” The Barion is an exception to the “modified” rule, because its name already embraces a variety of facet placement styles.

Please note that gem cuts in the brilliant style are always called brilliant cuts (for example, “round brilliant”),  while gem cuts in the step style generally have specific names attached to them (for example, Asscher or emerald cuts).

gem cutting styles - modified princess cut
A modified princess cut (named PrincessPlus) compared to a standard princess cut. Public Domain.

Cabochon Cuts

Gems polished into domes are called cabochons or cabs. These types of gems date back to ancient times and have remained popular in the centuries since.

Lapidaries cab certain gem species, such as opal and moonstone, to better display visual effects such as play of color, cat’s eye, and asterism. In faceted gems, these effects would be less visible. Some stones may be cut into cabochons because they’re lower quality or too opaque for faceting. Cabbing these stones would emphasize their color and luster rather than brilliance. Softer gem materials may also receive cabochon cuts, since cabs don’t show scratches as easily as faceted gems do.

Cabochons usually have circular or oval shapes. Sometimes, gem cutters may give them square or rectangular shapes. In those cases, they will show creases. Cabochons can be single cabs or double cabs. Typically, natural stones are polished into double cabochons to maximize weight.

gem cutting styles - cabochon
Lake Superior agate cabochon, Minnesota. Photo by Astynax. Public Domain.

Named Cuts

New gem cuts are created every day.

In a checkerboard cut, a faceter cuts the gem with square facets, so its crown and table resemble a checkerboard. This cut is often used on translucent stones.

A colorless 1.41-ct Mexican opal with a checkerboard top displays its play of color effect when illuminated. © The Gem Trader. Used with permission.

The divine cut, a round cutting style, allegedly gives a gem more sparkle, a higher perceived color grade, and a larger face-up appearance than round brilliants.

The snowflake cut is another refreshingly beautiful new design.

As a group, these creative but less frequently seen cuts are known as named cuts. As technology advances, the number of named cuts increases. Gem lovers will always drive innovation. However, not all named cuts are new.

Portuguese Cut

A traditional named cut, the Portuguese cut has several tiers of facets, which create a wonderful display of light. It has more scintillation than almost any other cut. As you can see from the photo below, the Portuguese requires many facets and considerable labor. These factors, in addition to the fact that the rough must have greater than normal depth, ensure that you’ll only see this cut occasionally.

Portuguese Round Diaspore - Gem cutting terms
Diaspore, 5-star Portuguese round, 10.90 cts, faceted by Stephen Kotlowski. © All That Glitters. Used with permission.

“No Name” and “New Name” Cuts

Some cuts have no name at all. Sometimes, faceters simply use a cut that fits a piece of rough, something that just “works.” The red gem below is a good example of this. It’s a simple cut with a radiant pavilion.

No name cut - gem cutting terms

When the GemCad program was released in the 1980s, people were able to test their gem cutting designs on a computer before taking a stone to a lap. This made it easy for people to create new cuts. Today, there are thousands of new designs. Many of these newly named cuts are simply a means to standardize common techniques. For example, someone may “design” the cut used on this red gem and save it with a computer program. They then have an established method for cutting it that can be referenced and used again. What was once a “no name” cut that just worked for one stone can now become a “new name” cut that could work with other stones.

While most newly named cuts are just variations on standard cuts, some are unique. Indeed, there seems to be no end to the imagination of our lapidaries. There’s no limit to shapes or the number and arrangements of facets. Some new cuts are merging a variety of techniques. Below is a Barion cut gem with a parallelogram outline.

Barion cut with parallelogram outline - gem cutting terms

Curved Facets

Flat facets aren’t the only technique available to today’s gem cutters.

Fantasy Cut

A fantasy cut is a popular style of faceting. This technique uses large pavilion facets. Some simple grooves are used, which are mirrored throughout the pavilion. This ametrine is an excellent example of a fantasy cut gem.

Fantasy Cut - gem cutting terms
Fantasy Cut Ametrine

Concave Facets

Hand cutting isn’t the only way to make precise, concave facets. There are now faceting machines that can accomplish this. The gems are first cut traditionally with flat facets. Then, they’re transferred to another machine for an additional set of concave facets. However, the extra labor required for this is so considerable that this technique is unlikely to see widespread use. Nevertheless, as you can see from the picture below, the results are nothing short of spectacular. The brilliance and scintillation exceeds anything that can be done with flat facets alone.

Concave facets - gem cutting terms

There is no end to what a lapidary can do with gemstones. Keep your eyes open and you’re sure to see cuts that are totally unique.

unique shapes - gem cutting terms
There are always new designs and unusual shapes for gem cutting.

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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About the author
Phoebe Shang, GG
A gem lover and writer, Phoebe holds a graduate gemologist degree from the Gemological Institute of America and masters in writing from Columbia University. She got her start in gemology translating and editing Colored Stone and Mineral Highlights for a professor based in Shanghai. Whether in LA, Taipei, or New York, Phoebe spends her time searching for gems to design and being lost in good books.
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