Diamond Knowledge

Diamond Characteristics & the "four C's"

Getting to Know Diamonds | Diamond Characteristics

This section contains imortant information about diamond characteristics, including the "four C's".

The "four C's"

The characteristics of a diamond are referred to as the “four C’s”, which stands for carat weight, colour, clarity and cut. You should always consider these characteristics when you buy a diamond. In addition to the “four C’s” other important features are fluorescence and diamond shape.

Carat Weight

Carat weight refers to the weight of the loose diamond. One carat equals 0.2 grams. A carat is further subdivided into 100 points. A stone of 1.60 carat therefore means it is 1 carat and 60 points.

Diamond Colour

The colour of a diamond is determined by comparing it to an approved set of international master-stones. With all examinations, each stone is graded with several grades before a decision is taken.

It is important to note that 90% of gem diamonds have a yellowish colour. Colour is as a result of the composition of the diamond and it never changes over time.

A colourless diamond is very much like a clear window which allows more light to pass through it than a coloured diamond. The way a diamond is formed ensures that only a few diamonds are truly colourless. Therefore, it can be concluded that the whiter the diamond's colour, the greater its value.

The "D" grading is the highest grading for the colour of a diamond. A "D" grading indicates that a diamond is colourless. This is the highest colour grade and it is therefore rare to find a diamond that falls into this category.

Please note that a diamond that has had its colour modified artificially must be mentioned in the section "Comments" on the certificate. (GS Diamonds do not carry any artificially enhanced diamonds).

Diamond Clarity

The clarity of the loose diamond is determined by the brightness and the location of both the external and the internal characteristics. Most diamonds contain "inclusions". Minute fractures within the stone may also be present. Once again, these are all part of the internal characteristics of the stone. It should be remembered that each stone is unique and this is why the internal characteristics of each stone vary.

The following characteristics are determining factors for clarity grading:

  • How quickly inclusions can be detected and whether they can be seen with the naked eye or with magnification
  • Appearance of inclusions
  • Nature of inclusions
  • Type of inclusions

A diamond is described as loupe clean when it is examined by an expert with a 10x binocular microscope magnification and found to be absolutely transparent and free from inclusions.

  • Very, Very Small inclusions in a diamond attract a VVS1 or a VVS2 clarity grade. These terms describe a diamond that when viewed through a 10x magnification loupe are very difficult to see.
  • Very Small inclusions in a diamond attract a VS1 or a VS2 clarity grade. These terms describe a diamond that when viewed by an expert using 10x magnification, they can discern very small inclusions which are difficult to see.
  • Small Inclusions in a diamond attract a SI1 or SI2 clarity grade. These terms describe a diamond that has inclusions that are relatively easy to find under 10x magnification.
  • The clarity grade P1-P3 or I1-I3, refers to cut diamonds which when viewed with 10x magnification, are obvious and visible to the naked eye. These inclusions are not a hindrance to the brilliance of the diamond.

Diamond Cut

Diamonds are cut in various fancy shapes. These include: round, princess, emerald, oval, pear, marquise, heart, cushion, asscher, radiant and trilliant. Among these cuts the classic is the round brilliant cut diamond. This style of cut has enjoyed the longest and most intensive development throughout its history.

The term brilliance is an important in understanding more about the cut of a diamond. This term involves several distinct optical processes in a diamond. These include: external brilliance, internal brilliance and scintillation brilliance.

In order to achieve a good ratio between brilliance and dispersion, the light should enter the stone at many different angles. A too deep or a too shallow cut diamond will not achieve the maximum beauty of light dispersion.

Only the cut can bring out the maximum beauty of the diamond. Even diamonds with inclusions, when perfectly cut, appear to be stunning jewels.