About Diamonds

If you're searching for the perfect diamond engagement ring, the variation in cost and quality of stones can be very confusing.  At de Klerk Jewellers we're always happy to explain the difference in the cut and quality of diamonds, and we'll always ensure that you can see a range of stones that are within your budget.


When purchasing a diamond the following information will assist you to make an informed choice when selecting a stone.

The classification of a diamond is based on the ‘Four Cs’: Carat, Colour, Clarity and Cut.


The primary thing in these four Cs is the cut quality. When a diamond does not have a good cut other components such as colour and clarity are no longer as apparent. The way in which a diamond is cut determines how much sparkle the stone will have. Of all the varieties of diamond cut, the brilliant rounded cut is most the most dynamic in regards to sparkle.



The Clarity of a diamond depends upon the number flaws present in a particular stone. There are different categories that define the degree of these flaws. The highest quality diamonds are said to be ‘Flawless’ ( FL) and others are categorised as ‘Slightly Included’ (SI) which indicates flaws are present, which may vary in degree as indicated in the chart below.

Commercially available diamonds are graded as SI1, SI2 etc meaning Slightly Included 1, Slightly Included 2 and so on. The higher quality in this grading are said to be VS and VVS. meaning ‘Very Slightly Included’ and ‘Very Very Slightly Included’.


Colourless diamonds are the purest form of diamond, and they will be bright white in appearance.

The colours of diamonds are categorized in the diamond market, they are purely based on its colour and colourless attributes. These attributes are grouped into many clusters based on the stones properties, and these clusters are identified via the following letters: D, E, F, G-H, I-J & K, L-M, N-Z.

Clusters D, E and F are said to be colourless diamonds. In these clusters, the D type is very rare and is absolutely colourless. E and F based stones possess a tiny amount of colour that can only be detected with an experts assistance. G-H diamond clusters are said to be near colorless. Colour detection is visible when compared with higher grade diamonds. Other clusters indicate the varying degrees of colour present.



Besides color, clarity and cut, weight provides a further basis in the valuation of a diamond.

The weight of all gemstones is measured and counted in carats, commercially abbreviated to “ct”. According to CIBJO regulations the carat weight noted: “The weight of a diamond is to be indicated to the second decimal point; the international abbreviation is ct.”

It is only since the beginning of this century that the carat weight has been adapted to the metric system and is now used-internationally.

The unit of weight is established as follows: one metric carat = 200 mg = 1/5 gram.