6 Things to Know Before Buying a Diamond

Click here to get our downloadable PDF. 

For many years, the diamond has held the title of the most sought-after gemstone. It is seen as the greatest symbol of love, making it the perfect gift for special occasions. Before make your purchase, however, there are 6 things that you need to know so that you can make an informed decision.


The value of a diamond increases as it becomes more colourless. The colour scale of a diamond ranges from D (the most colourless, called a blue white) to Z (contains colour).

The exception to this is fancy colour diamonds, e.g. blue, red, and pink.

2. CUT

The cut is considered to be the most important of the four Cs. If a diamond is not cut to the correct proportions, it will not sparkle as much as it could.

The most popular cut is the round brilliant, the dimensions of which are created according to a mathematical formula that maximises brilliance and fire.


The clarity of a diamond refers to how many imperfections (called inclusions) exist in the stone. These appear as specks or lines inside the stone. The fewer inclusions, the higher the clarity, and the more valuable the stone.

The clarity of a diamond ranges from FL (flawless, i.e. no inclusions at 10x magnification) to VS1/2 (very slightly included, i.e. inclusions are barely visible at 10x magnification) to I3 (visible inclusions with no magnification).


The term "carat" (ct) refers to the weight of a diamond, where 1 carat equals 0.2 grams. The bigger the carat of the diamond, the more valuable it is.

Popular sizes (in a round brilliant cut) are:

  • 0.70 - 0.89ct = 5.8 - 6.1mm in diameter
  • 1ct = 6.5mm in diameter
  • 2ct = 8.2mm in diameter
  • 3ct = 9.4mm in diameter


Just like a work of art, proportions are important when creating a piece of jewellery. You may choose the perfect diamond, but if it is not set in the right proportions with the band and surrounding stones, then its appearance may be diminished.


If you are thinking of purchasing a diamond, you must ensure that it comes with a certification from a recognised industry body to ensure its authenticity.

Some of these bodies include:

  • Gemological Institute of America
  • European Gemological Laboratories (E.G.L.)


Got questions that we haven't answered here? Email us at info@markwhitehorn.co.za and we'll be happy to answer them. 

Keep well and stay safe! X