Diamonds are one of the most brilliant and beautiful elements found on earth. And, because they are also rare, a natural diamond can also be very valuable, depending upon the quality of the diamond. To help jewellers and you to better compare quality in diamonds, the GIA – the benchmark in diamond grading throughout the world – developed a universal grading system and the 4C’s.

The 4C’s includes cut, clarity, colour and carat weight. Each of these four characteristics is important and interrelated as they are used to determine the diamond’s value. It is commonly assumed that clarity is the most important of the 4C’s, yet colour and cut actually have a more profound affect on the visual appearance of the diamond than most diamond consumers understand.

In a series of four posts, we will discuss the 4C’s and their impact on the brilliance and subsequently, the value of your diamond.

For this first post, we will take a look at the cut of the diamond and the importance of this C in the diamond’s value. The first important point in the cut of the stone is that is refers to your diamond’s proportions and angles more than the shape of the diamond you are considering for purchase.

The cut of any diamond will have three attributes:

1. Brilliance – the total light reflected from a diamond
2. Fire – the dispersion of light into the colours of the spectrum
3. Scintillation – the flashes of light captured when the diamond is moved.

It doesn’t matter if a diamond is round, marquise, pear, princess or other any other shape, it gets its brilliance and scintillation by how exact the cutting and polishing of the diamond facets adhere to the ideal proportions. This process is actually worked out mathematically to deliver the optimum “Fire and Brilliance”. It also determines the amount of light that enters through the top of the diamond to be reflected and dispersed back through its top.

If a diamond is perfectly cut so that all angles and proportions are within correct guidelines, the light that enters the diamond is dispersed properly back through the diamond’s top facets. In a traditional brilliant round cut diamond, 58 facets are each precisely cut and defined and can be as small as two millimeters in diameter.

This precision is essential in the cut of the diamond or it wouldn’t be nearly as beautiful and would fail to disperse the light properly to achieve the brilliant fire display. Consider a science experiment you may have done in high school in which the light from a torch was pushed through a prism of glass or Perspex and on the other end the light would break up into the colour spectrum.

This is the exact process diamonds use to disperse and break up the light into the “Fire” that is visible when it is moved and rotated. In understanding this experiment, you understand how the “Fire and Brilliance” are achieved when the diamond cut meets the exact mathematical proportions and angles to achieve MAXIMUM sparkle.

If the stone is cut too shallow or too deep, the light entering through the top of the stone would not be allowed to escape through the bottom of the diamond and the beauty of the stone is at the very least dampened and most often lost.

Once you have a clear understanding of the importance of the cut of the diamond, you can then focus on its shape. Most diamond jewelry relies on the round brilliant diamond, and all other shapes are known as fancy. While cushions, marquise, pear, oval and emerald cuts are more traditional fancy shapes, cushions, hearts, triangles, briolette and others are gaining popularity as consumers aim to try something new.

Cut is easily referred to as the ‘forgotten’ C, but without your focus on how well the diamond is cut, it cannot meet its maximum brilliance. A diamond cannot be cut for weight or shape alone and if the stone doesn’t catch your eye or flash in the light, this is most likely due to a poor cut rather than poor quality in the stone.

The way the diamond is cut to reflect its brilliance is as important as the colour of the diamond you choose. Essentially, the cut and colour form the “heart and soul” of your diamond. Join us next time for a further look into the 4C’s as we examine Colour.

Diamond Cut - these are some of the most important factors to consider when buying a diamond.