4Cs of a Diamond

A diamond’s value is dependent on its intrinsic qualities, which are what we know as the 4Cs - Carat, Color, Clarity and Cut. This has been adopted as an industry standard which is widely used in the grading of a diamond. As such, purchasing a diamond has been more transparent than ever.

A carat is a unit of measurement used to determine the weight of a diamond and is the equivalent of 0.2 metric grams. It is commonly mistaken for the size of a diamond which is what people care about, but it is an understandable mistake as size increases with weight. Due to the fact that larger diamonds are much rarer than smaller stones, the price of a diamond increases more than proportionately to its carat.

However, It should be noted that carat weight is not the only variable that affects the aesthetic appearance of a diamond. There are many other factors that affect how large a diamond may look. For example, a diamond with a better cut is able to shine brighter and hence appear to be larger to the naked eye. In addition, the proportion and shape of a diamond could affect its surface-to-depth ratio, giving the perception of a larger stone.
In some cases, the design of the ring could also affect the appearance of the diamond as well. In halo ring designs, the feature stone is surrounded with smaller melee diamonds, and this collectively helps to provide a visual augmentation to help the main stone appear larger as well.

While the carat of a diamond plays a significant role in the determination of its overall price, it is important not to overlook the other three grading standards - color, clarity and cut.



The color description of a diamond in actuality describes the degree of absence of color in a diamond. A purer, and thus more valuable diamond, would be colorless, while a diamond with a tint would be comparatively less valuable, unless it were of a deep colour, which would then make it a coloured diamond, and potentially even more valuable.

In the gemological laboratories, to grade the color of a diamond, the stone analysed under controlled lighting conditions against benchmarks to determine the stone’s color. The color of a diamond is measured on the color grading scale, which ranges from D to Z.

These grades are also usually banded together. For example, a color grade of D to F would correlate to the ‘colourless’ band, whereas a color grade ranging from G to J would correlate to the ‘near-colourless’ band.

Colour Grade Description:
D to F    Colorless
G to J    Near-colorless
K to M    Faint
N to R    Very Light
S to Z    Light

In general, the color of two diamonds can usually only be differentiated when they are at least two grades apart. The difficulty increases when the diamonds are set in the jewelry as the reflection of the metal would also impart some color upon the diamond. We often recommend the use of a white gold or platinum band with a colourless diamond to allow the diamond to retain as much of its colourless property as possible, and possibly a yellow or rose gold band for those with a slight tinge of yellow. In addition, in a ring setting, a diamond’s predominant profile is its top which tends to appear more colorless, as compared to its side profile.

As a diamond is formed under intense heat and pressure, internal characteristics known as ‘inclusions’ and external characteristics known as ‘blemishes’ can be imparted. These characteristics would affect the clarity grade of a diamond. To examine these characteristics, the diamond grader analyzes the diamonds under magnification and plots out the position of these inclusions and blemishes (if any). There are various evaluation criterias involved in the determination of the clarity grade of a diamond, including the number, size, relief, nature, and position of these characteristics and how they affect the overall appearance of the diamond. For example, a diamond with an inclusion that appears close to the center of the crown would result in a lower clarity grade than another with a similar inclusion that is positioned nearer to the girdle of the diamond, all else being equal.

The clarity grading scale is divided into six categories. While the different clarity grades may look similar to the naked eye, the value of two diamonds with different clarity grades can diverge greatly. A dubious jeweler could instead use terms such as ‘piqué’ or ‘loupe clean’ to hide the actual quality of the stone. Hence, it is important to be informed and to demand the usage of the standard clarity grading scale instead.

As these inclusions and blemishes are often imperceptible to the untrained naked eye, we would be advice those on a budget to pick the right diamond with subtle and well hidden inclusions such as those which might be nearer to the girdle or blocked by the design and prongs of the setting.

A diamond’s cut affects its ability to interact with light and is the only attribute of the 4Cs that is not naturally occurring. Instead, this attribute tests a craftsman’s skill in cutting a diamond to perfection. Good craftsmanship imparts perfect proportion, symmetry and polish, maximising the brilliance and hence the aesthetic appearance of the diamond.

Many would note that among the 4Cs, the cut of a diamond is the most crucial. That being said, the grading of a diamond’s cut is also the most complex and difficult to grade. The grading of a cut takes into account the design as well as the craftsmanship of the diamond. There are multiple factors that are considered including the girdle thickness, ratio of average table size to average girdle diameter and many other measurements.
A diamond can be graded into one of the five diamond cut grades, ranging from excellent, very good, good, fair to poor. A well cut diamond will maximize its interaction with light to create desirable visual characteristics such as brightness, fire and scintillation.

While the cut of the diamond is important, the actual grade of it might not be as important as what is visible to the naked eye. As long as the proportions are within acceptable ranges with a clear view of its “hearts & arrows” under an Aset scope, this is what we value more when choosing an affordable diamond for you.

Carat Weight