The cut of a stone is one of the four factors determining its quality (the other three are clarity, color, and carat). Not all cuts are the same. Some have a purpose beyond being aesthetically pleasing, while others try to maximize another quality at the expense of a great cut (as is often with colored gemstones). For a basic overview, there are a few identifying parts of the stone:
• Table – The flat top part of the stone.
• Crown – Below the table, the flat facet around the top of the stone.
• Girdle – A thin band surrounding the stone. It is the bridge between the crown and the pavilion.
• Pavilion – The bottom, faceted part of the stone.
Aspects such as the crown height, cutlet (facet), and pavilion depth are essential for seasoned jewelers. It is necessary to point out that the stone's depth (mainly the pavilion) will affect the color of the stone. A shallow stone will be too clear to see through, while a deep stone will appear much darker or tenebrous. Even this, however, can vary on the locations of the color, inclusions, and whether or not less or more color is coveted. Below are some of the most popular diamond cuts. Many of these cuts have found their way in other stones too.
The brilliant cut tries to optimize or amplify the brilliancy; in other words, that "sparkling light" effect you see in stones. Historically, this was one of the most popular diamond cuts. Today it has found use in some colored gemstones. The brilliant cut surpassed the old "rose cut" that was formed sometime around the 18th century. Diamonds were items of opulence for their extravagance, glamor, and pulchritude; they were an expensive novelty. The cut's optimization became regnant to maximize the effect of the stone's beauty. Brilliant cuts are sometimes merged with other cuts (these are "mixed-cuts"), but there is confusion in the history of cuts. This is due to a lack of consistency in terminology in the past and between different regions. In other words, there was more than a simple "brilliant cut." The U.S. National Museum in 1921 published a bulletin that mentioned the "double brilliant" cut, a "half-brilliant", and a "trap brilliant" among others. Today, however, these seem to be cuts that are familiar to jewelers today but go by another name. The "double brilliant" may be no more than a special kind of cushion cut. The typical "round brilliant" has 57 facets.
While brilliant cuts can confuse some, especially when examining them historically, step cuts are relatively straightforward. As the name implies, the jeweler cuts the stone in steps with parallel facets. Common step cuts include the baguette cut, the oval step cut, the square cut, and the emerald cut. While the brilliant cut maximizes a stone's grandeur or brilliancy, the step cut achieves the opposite: it minimizes brilliancy. This may seem strange at first because brilliancy is what makes a diamond so highly coveted. But remember, one of the four Cs is "color." Colored gemstones or colored diamonds, not clear-white diamonds, typically have step cuts for clarity. It is also useful for weaker, softer stones because it leaves few if any, fragile edges.
An old, traditional cut also historically used for diamonds and was likely developed in India. It was once among the most popular diamond cuts. As the name implies, it resembles the shape of a rosebud. Some use this cut for colored stones today. Rose cuts have a faceted dome shape with a flat bottom. The only case where it has a faceted bottom is when it is a double rose cut, where it mirrors the top portion of the gemstone. A standard rose cut has 24 facets. Smaller stones may have this cut or style.
The cabochon cut has a similar shape as the rose cut but is non-faceted and has a smooth dome shape. The significance of this cut and its acclaim can be attributed to its goal. It tries to preserve coveted or special visual properties. Stones that display asterism (a star-shaped reflection of light on a stone's surface) and fluorescence usually have this type of cut to not hurt or remove the property entirely.
These cuts don't have a single type. They use both a brilliant and step cut to maximize whatever the cutter needs. This is usually a combination of color and brilliancy, but removing flaws (such as inclusions) for better clarity is equally important. There are no specific styles or types to single out because there isn't a standard for mixed cuts. The only exceptions to this rule are a trade cut performed by a company or artisan.
Companies and artisans may use "fancy cuts" for their stones in addition to the cuts described above. Much like the mixed cut, most of these cuts don't have a universal standard though a few patterns stand out, such as the "marquise cut" or any heart-shaped cut.
Asymmetrical cuts with no pattern are sometimes called "native-cuts" (an outdated term referring to the types of people who cut them, but it nonetheless persists in the modern-day). These cuts are usually, but not always, performed with old, imprecise cutting tools such as a jam-peg machine. Some see them as ugly as they crudely try to accentuate or maximize the four Cs as simply as possible without any regard for symmetry or proportion. However, hardline traditionalists miss the goal of this type of cut. The purpose of this seemingly "ugly" cut is to produce the best color quality possible. Therefore, we may call it a "color cut."
Traditionally, the cut's goal is to maximize the four Cs with as much attention and precision to proportion as possible. This was until the invention of the so-called "fantasy" cut. Even less standard than mixed or fancy cuts, fantasy cuts almost always unique. Munsteiner is one of the leading pioneers of the fantasy cut movement. Criticism came his way when he started work in 1960. However, since then the public and lapidaries alike have praised the unique artistic styles he introduced.
"And Then Came the Fantasy Cut." GIA, www.gia.edu/munsteiner-gem-cut.
"The Magic of the Fantasy Cut Gemstones." GIA 4Cs, 4cs.gia.edu/en-us/blog/magic-fantasy-cut-gemstones/
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