Diamond Cut, Symmetry and Polish

When it comes to buying engagement rings, most people are familiar with the 4 C’s of diamonds: cut, color, clarity, and carat weight. However, there are other important factors to consider when choosing the perfect diamond for your loved one, such as the polish and symmetry of the stone.

Many jewellers will group cut, polish, and symmetry together when discussing diamonds. In fact, a triple X ring is one in which the cut, polish, and symmetry of the diamond are all graded as excellent. The possible grades for each factor are excellent, very good, good, fair, and poor.


Of these factors, cut is perhaps the most important. The cut of a diamond determines how well it interacts with light, which in turn affects the diamond’s fire, brilliance, and scintillation. Fire refers to the internal white light reflection within the diamond, while brilliance refers to the external white light reflection. Scintillation is the overall sparkle of the diamond. These three factors work together to create a beautiful and dazzling diamond.


Symmetry is another important factor to consider when buying a diamond. It refers to how well the individual facets of the diamond are intersecting and aligned. A higher grade of symmetry will give the diamond a greater brilliance, as the light will be reflected more evenly. On the other hand, a diamond with poor symmetry will reflect light incorrectly, creating odd angles and a less dazzling appearance. While it is difficult to differentiate between a good and an excellent symmetry, it matters more for diamonds of higher clarity, VVS2 and above.


Finally, a diamond’s polish also plays a role in its overall appearance. The polish refers to how smooth the facets of the diamond are. A rough polish can obstruct light and change the light patterns, resulting in a less brilliant diamond. A poorly polished diamond may have smudges or appear gritty. While polishing defects are usually not visible to the naked eye, they can be detected under intense magnification. As a general rule, for any carat weight below .75ct, a polish grade of fair and above is appropriate, as any issues would not be visible to the naked eye.

When it comes to buying an engagement ring, it’s important to remember that there is more to diamonds than just the 4 C’s. The cut, symmetry, and polish of a diamond can all affect its overall appearance and brilliance. By working with a trusted jeweller, you can rest assured that you will find the perfect diamond for your loved one that will last a lifetime. For more information about diamond polish and symmetry, see here.

At Commins and Co, we understand that choosing the perfect diamond can be overwhelming. That’s why we are committed to delivering the highest quality diamond to suit your budget and taste. Our team of experts can guide you through the diamond buying process, helping you to find the perfect diamond that meets your needs and exceeds your expectations. See here for more advice for buying diamonds and engagement rings.