The Quality of the Cut Diamond

Quality is Most Important

The quality of the cut diamond is widely considered the most important aspect in determining the beauty of a diamond. It is commonly admitted that a well-cut diamond may appear to be of greater carat weight, and have clarity and color of a greater grade than they actually have. The skill with which a diamond is cut by the diamond cutter determines its ability to reflect and refract light thus exhibiting superior value.

The Cut is Tough to Judge

Besides carrying the most importance to a diamond’s quality as a gemstone, the cut of the diamond is also the most difficult to judge. Many  factors — including proportion, polish, beauty and balance as well as the relative angles of various facets — are determined by the quality of the cut and can affect the performance of a diamond. A diamond with the 57 facets cut only a few degrees out of alignment can result in a poorly performing stone such as looking dull or off-color.

Mistaken Identity

A round cut diamond with too much fire may appear as a cubic zirconium which gives off much more fire than a true diamond. An inferior cut diamond will appear dark in the center and in some cases there may be shadows when viewed from the table. The quality of the cut diamond brings forth different theories on the “ideal” proportions of a diamond and continue to be advocated by various owners of patents on machines to view how well a diamond is cut.

The science and skill required to shape a rough diamond into a beautiful polished gemstone is an art in itself. The choice of cut is often decided by the original shape of the rough stone, location of the inclusions and flaws to be eliminated, the preservation of the weight, popularity of certain shapes amongst consumers and many other considerations. The round brilliant cut is preferred when the crystal is an octahedron, as often two stones may be cut from one such crystal. Odd-shaped crystals more than likely will be cut as fancy diamonds.

The quality of the cut diamond generally results in over 50% of the original weight being lost during the cutting and polishing process. Since such a premium price is awarded to the 1.00-carat stone the consumer would be well advised to consider buying a 1.10-carat or a 0.99-carat perfectly cut diamond rather than what could turn out to be an inferior cut 1.00-carat diamond.

Many Factors to Consider

The term light performance is used in the gem trade to describe the amount of light that will return to the viewer from within the diamond. There are three light properties which are taken into consideration in relation to light performance: brilliance, fire, and scintillation. Brilliance refers to the white light reflected from within the stone. Fire refers to the spectral colors as the diamond disperses the white light and scintillation refers to the small flashes of light from within the stone as the diamond is turned. All of course affect the quality of the cut diamond.


Diamond Cutters – Do They Really Cut Them?

When we discuss diamonds, we often hear about diamond cutters, but do they really cut diamonds and if so, how is it done?

In grading diamonds,  there are four categories that must be considered before the value of the diamond is determined — cut, clarity, carat and color.

So to answer the question — Do diamond cutters really cut them?

Diamond crystals are octahedron-shaped. The great pyramids of Egypt are in the shape of polyhedrons with four faces and six edges. Imagine a pyramid with another pyramid bottom up underneath and you will have an octahedron. The raw, loose diamonds arrive at the diamond-cutting factory as octahedrons and must be cut in two in the middle before they can be shaped and polished into polyhedrons — the shape we see today in diamond gemstones.

The hardest mineral

Diamond is the hardest element and only another diamond will cut it. At the factory, the craftsman will examine the octahedron, determine the exact middle between the two soon-to-be polyhedrons and draw a fine line where the two meet. To cut the stone, a round, thin metal blade impregnated with diamond dust and spinning at a high rate of speed is used. The diamond is held on both ends with a special holder and lightly comes into contact with the blade. As the blade turns, the diamond dust will slowly wear a groove in the stone and after time passes, the octahedron will be halved thus creating two pyramid-shaped polyhedrons. This cutting process will take approximately 24 hours for a one-carat diamond. So now we have the answer — diamond cutters really do cut diamonds!

In the next step, the pyramid-shaped rough diamonds will go through the process of shaping and polishing where approximately 50% of their volume will be lost. This will be a long process as the 57 facets will be ground into specific dimensions and polished to perfection.

It takes many calculations

It took a mathematician to figure out the precise angles and numbers to create the perfect combination of facets and angles to bring out the pure beauty of the modern-day diamond. Prior to this, as much as possible of the stone was retained without consideration for the brilliance contained within. His calculations guide the diamond cutters today as they ply their exacting trade.