Diamond Cut is perhaps the most important of the four Cs, so it is important to understand how this quality affects the properties and values of a diamond.
A good cut gives a diamond its brilliance, which is that brightness that seems to come from the very heart of a diamond. The angles and finish of any diamond are what determine its ability to handle light, which leads to brilliance.
As you can see in the image below, when a diamond is well-cut, light enters through the table and travels to the pavilion where it reflects from one side to the other before reflecting back out of the diamond through the table and to the observer’s eye. This light is the brilliance we mentioned, and it’s this flashing, fiery effect that makes
In a poorly cut diamond, the light that enters through the table reaches the facets and then ‘leaks’ out from the sides or bottom of the diamond rather than reflecting back to the eye. Less light reflected back to the eye means less brilliance.
Don’t confuse diamond cut with shape. Shape refers to the general outward appearance of the diamond, not it’s reflective qualities.
Good Porportions are key
Most gemologists agree that the best cut diamonds are those that follow a set of formulae calculated to maximize brilliance. These formulae can be seen in a diamond’s proportions, most importantly how the depth compares to the diameter, and how the diameter of the table compares to the diameter of the diamond.
One of the leading diamond grading bodies, the AGS, has developed a table which they believe offers the the “ideal” proportions of diamond. The image below details the various parts of the diamond, together with the recommended proportions of the AGS.
Because cut is so important, several grading methods have been developed to help consumers determine the cut of a particular diamond. In general, these grades are Ideal, Excellent, Very Good, Good and Fair.
meter: The width of the diamond as measured through the girdle.
Table: This is the large, flat top facet of a diamond.
Crown: The upper portion of a cut gemstone, above the girdle.
Girdle: The narrow rim of a diamond that separates the crown from the pavilion. It is the largest diameter to any part of the stone
Pavilion: The lower portion of the diamond, below the girdle. It is sometimes referred to as the base.
Culet: The tiny facet on the pointed bottom of the pavilion, which is the portion of a cut gem below the girdle.
Depth: The height of a gemstone, from the culet to the table.
Which Grade Should I buy?
Selecting the grade of cut is really a matter of preference. To make the best selection, you need to understand the various grades. Universal Jewelers grades its diamonds as Ideal, Very Good, Good, Fair or Poor.
Ideal: Diamonds that are described by Universal Jewelers as Ideal have a make which is considered fine by anyone in the industry. This cut is intended to maximize brilliance, and the typically smaller table sizes of these diamonds have the added benefit of creating a great deal of dispersion or ‘fire’ as well. Ideal quality diamonds are truly for the person who enjoys knowing that he has one of the finest things that money can buy. This category applies only to round diamonds
Diamonds that are described by Universal Jewelers as Premium have a make which is considered fine by anyone in the industry. In the case of round diamonds, many of these diamonds have cuts that are the equal of any Ideal Cut diamond, though they often can be purchased at slightly lower prices than AGS Ideal Cuts. They are intended to provide maximum brilliance and fire. They are truly for the person who enjoys knowing that he has one of the finest things that money can buy.
Diamonds that are described by Universal Jewelers as Very Good are of a excellent make. They reflect most of the light that enters them, creating a good deal of brilliance. With these diamonds, the cutters have chosen to stray slightly from the preferred diamond proportions in order to create a larger diamond. The result is that these diamonds fall slightly outside of some customers’ preferences in terms of, for example, table size or girdle width, though, in many cases many of the parameters of diamonds in this range will overlap with certain parameters of diamonds in the Ideal or Premium ranges. Generally, the price of these diamonds in slightly below that of Premium cuts.
Diamonds that are described by Universal Jewelers as Good reflect much of the light that enters them. Their proportions fall outside of the preferred range because the cutter has chosen to create the largest possible diamond from the original rough crystal, rather than cutting extra weight off to create a smaller Premium quality diamond. Diamonds in this range offer an excellent cost-savings to customers who want to stay in a budget without sacrificing quality or beauty
A diamond described by Universal Jewelers as poor will reflect only a small proportion of the light that enters it. Typically these diamonds have been cut to maximize the carat weight over most other considerations. We do not recommend this type of cut and to ensure that our customers enjoy only fine, classic jewelry, Universal Jewelers does not offer diamonds that have been graded fair to poor.