The cut of a diamond does in part have to do with the shape of a diamond. Shape does affect the price of a diamond with round diamonds being the most expensive cut and the other fancy shapes falling below at varying levels. This is because round diamonds are the most brilliant and have the most specific scientific grading specifications for a perfect cut. The most important aspect of the cut quality is the proportion to which a diamond is cut. The proportion and symmetry of a diamond determines how well a diamond will refract the light producing the scintillation and brilliance a diamond should display.
The quality of the cut is very important not only to how a diamond will look but also how the diamond displays it’s colour and hides the clarity of the diamond. Cut also plays a very significant role in the price of a diamond altering the price in some cases up to fifty percent. As the quality of a diamond’s cut involves several minor and major factors it can be a little difficult for the average customer to establish this quality. The best way to check a diamond’s cut is to buy a diamond with a reputable certificate.
Diamond certificates have two to three final grading scores that take all the measurements of the diamond and summate them into a verbal scale. The categories are Cut, Finish and Symmetry graded to either Excellent, Very Good, Good or Poor. The Finish of a diamond is how well the surface of the diamond is refined and polished to remove graining and scratches off the facets. This is probably the least important category with even a “Good” grade being quite an acceptable purchase. The cut is the measurement of the proportions to which the diamond is cut and the overall performance of the diamonds brilliance. A poorly cut diamond will often be smaller in diameter and holding extra weight at the base of the diamond. Although it may look impressive under the intense lights of a showroom, in natural light much less of the light is refracted directly back through the top of the stone.
The difference between an “Excellent” and “Very Good” quality cut is only slight but does become apparent above a carat weight of 0.80ct to a discerning eye. A “Very Good” cut is quite acceptable for most clients looking for a high quality diamond. They are very near to perfect proportions in all of the measured quantities and produce an exceptionally brilliant diamond. For those clients wanting absolute perfection where every facet of the diamond is visually stunning an “Excellent” cut and symmetry is essential.
A diamond’s symmetry grades the relationship of the facets. How proportionate they are in size and relation to each other. Each corresponding facet should lie on exactly the same angular plain and be the same size. When the symmetry is perfect each facet can be seen individually and you can see the perfect alignment with the naked eye. Without a precise symmetry a diamond’s sparkle with be uneven and the facets will be indiscernible. When both the cut and symmetry are of a “Very Good” to “Excellent” grade any inclusions the diamond may have are disguised extremely well and how the diamond presents it’s colour can be improved by up to two grades. We believe that when selecting a diamond that Cut quality is the most essential decision to be made regarding the 4 C’s as it can have the greatest influence on the other three grades and is not commonly explained by retail sale consultants.