A diamonds beauty comes from not only the favorable body color but from the optical properties like a high refractive index and color dispersion.
It requires precision, calculated planes and angles used in the cut to get the desired beauty. The brilliance of the stone is determined by cut, width, depth, roundness, size and how the facets are positioned. Despite brilliant cut and clarity, if it is not cut in good proportions, it will appear dull and less attractive.
Understanding The Science Of Diamonds
Early on, the guidelines for diamond cutting were based more around the beauty than science. In 1900, the round brilliant cut had become very close to the current form it takes today. In 1919, Marcel Tolkowsky, who is a member of a Belgian diamond cutting family, wrote a short paper called Diamond Design.
It was the first analysis of cutting diamonds based on modern light behavior theories. Even though the paper was first published in England, Tolkowsky’s design is often referred to as the “American Ideal Cut” because the cutters in the United States were the first to produce them in mass quantities.
During the 1950’s, Tolkowsky’s cut was adopted be AGS as its standard grading for a cut. The only changes made to the original design were creating ranges for table size, crown height, pavilion depth and girdle thickness. The updated model was renamed the AGS Ideal Cut in 1955.
The demand for the Ideal cut diamonds has increased over the years and today many diamond cutters all over the world are creating designs loosely referred to as “Ideal Cuts.” The standards for these “ideals” vary greatly and because of this, recognizing and evaluating cutting variations has become quite important. The popularity of “Ideal cuts” and the increase in demand from consumers for verification of quality are the primary reasons the AGS Laboratory was established.
It opened in 1995, and has quickly grown because it is the only facility in the United States that addresses cut grading in Diamond Quality Documents. The (GIA) Gem Trade Laboratory, the industry’s leading source for diamond quality documentation, does not discuss grade cuts in its released reports.
Princess Cut Diamonds
The Princess cut is square cut and has sharp edges. There is a high degree of brilliance and fire with this cut. It uses the most original shape of the rough diamond and the weight that is lost during cutting is very little. This results in a price that is more appealing than a round cut of comparable weight. This cut has many sparkling facets and is relatively new. It’s often found in solitaire diamond engagement rings.
It is a flattering cut for a hand with long fingers and can often be embellished with triangular stones at either side of the diamond ring. Because of its design, the cut needs more weight directed toward the depth of the diamond to give it the maximum amount of brilliance. It’s not unusual to see a depth percentage of 70% or 78%.
Most square of rectangular cuts don’t compare to the round brilliant when it comes to sparkle, but the Princess cut was designed for maximizing the brilliance from a square cut.
The Princess cut should be set so that the four pointed corners are protected. They will chip easily if not and that is why most square and rectangular cuts have corners that are cropped. If the length to width ratio is less than or equal to 1.05:1, the stone will appear square. While a square diamond is preferred by many, others like a more rectangular-shaped Princess.
Emerald Cut Diamonds
An Emerald cut is sleek and elegant, rectangular with cut corners. It’s considered a step cut which means its facets are broad with flat planes resembling stair steps. The higher quality Emerald Cuts are preferred because of the inclusions and lower color grades are more noticeable than others.
This can be an absolutely stunning cut. The long lines make it less fiery than “round brilliant” cuts but it tends to have broader, more dramatic light flashes. The trim lines give it an elegant, sophisticated look to both simple and elaborate settings.
When purchasing an Emerald cut diamond, it’s important to inspect the quality and select the highest grade that is affordable. Because the cut is so open, flaws, weakness in color, and a generally poor cut are more noticeable to the naked eye than with a cut like the “round brilliant.” This cut tends to be less traditional than others, so their pricing is more economical than the more popular diamond cuts.
The length to width ratio that fits the 1.35:1 is the most sought after. However, the square Emerald cuts have become more popular in diamonds in recent years.