Fei Liu


The 4 Cs of a diamond are the essential criteria used to determine a diamond’s quality and value. These Cs are carat weight, cut, colour and clarity.


Carat is one of the 4 Cs of diamonds, and it refers to the weight of a diamond. One carat is equivalent to 0.2 grams or 200 milligrams.

Diamonds are sold by weight, and larger diamonds are generally seen to be more valuable than smaller diamonds. However, the value of a diamond is not just based on its carat weight but also takes into account other factors. The other Cs – cut, colour, and clarity – also play an important role in determining a diamond’s value and beauty.

It’s essential to note that two diamonds of the same carat weight may have different values based on their cut, colour, and clarity. In some cases, a smaller diamond with superior cut, colour, and clarity may be worth more than a larger diamond of lower quality.

When selecting a diamond, it’s essential to consider all of the 4 Cs and how they work together to create a gemstone. Ultimately, the choice of carat weight comes down to personal preference and budget, but it’s important to choose a diamond that balances size with quality.


Cut is one of the 4 Cs of diamonds, and it refers to how well the diamond has been cut and polished. A diamond’s cut affects its overall appearance, brilliance and sparkle.

A well-cut diamond reflects and refracts light in a way that maximizes its brilliance, fire and scintillation. The cut of a diamond is determined by the diamond cutter’s skill and precision, as well as influenced by factors such as the diamond’s shape, depth and proportions.

There are several cut grades used to evaluate a diamond’s cut quality, ranging from Excellent to Poor. The cut grade considers various factors such as symmetry, polish, proportions, and overall craftsmanship.


Colour is another one of the 4 Cs of diamonds and it refers to the absence of colour in a diamond. Most diamonds appear colourless, but some have hints of colour that can affect their value and beauty.

Diamonds are graded on a colour scale that ranges from D (colourless) to Z (light yellow or brown). The less colour a diamond has, the more valuable it is considered. The colour grading is determined by comparing the diamond to a set of master stones that represent different colours on the scale.

The subtle differences in diamond colour can have a significant impact on the diamond’s appearance and value. Diamonds that fall within the D to F range are considered “colourless,” and they appear bright, sparkling, and highly desirable. Diamonds in the G to J range are considered “near-colourless” and still appear quite bright and sparkling but may have a slightly yellowish tint that is only visible under close inspection.


Clarity is one of the 4 Cs of diamonds, and it refers to the presence of internal and external imperfections, called inclusions and blemishes, respectively. The clarity of a diamond is determined by how many and how visible these imperfections are when viewed under magnification.

Diamonds with fewer inclusions and blemishes are considered more valuable. The clarity scale ranges from Flawless (FL) to Included (I3), with Flawless being the most valuable and I3 being the least valuable.

A diamond’s clarity can affect its appearance, as inclusions and blemishes can interfere with the passage of light through the stone, reducing its brilliance and fire. However, not all inclusions are created equal, and some may be less noticeable or even enhance the diamond’s unique character.