Is often confused with the outward appearance of a diamond, which relates to its ‘shape’ (round, emerald, pear, etc), because many ‘shapes’ are in fact called ‘cuts’ – including the Tycoon Cut and the Flanders Brilliant Cut. The fact is however that the ‘cut’ is what determines the way in which light travels through a diamond and reflects back into your eye.

If you compare diamonds on Carat Weight alone, as many people do, you can buy a ‘one carat’ diamond for $7,000 or $8,000 and think you have a bargain, when in fact you have paid too much.

This why Cut is given priority over Clarity, Colour and Carat Weight, however it takes an experienced eye to see the difference between a well proportioned diamond and a poorly cut stone.

Diamonds are created by nature under incredible pressure that can cause specific characteristics, known as blemishes or inclusions. Diamonds without flaws or inclusions, are more highly valued because of their rarity and these are graded according to the following system.

• F – Flawless:
  No internal or external flaws. Very rare.
• IF – Internally Flawless:
  No internal flaws, but some surface flaws. Very rare.
• VVS1 – VVS2:
  Very Very Slightly Included (two grades). Minute inclusions very difficult to detect under 10x magnification by a trained gemologist.
• VS1 – VS2:
  Very Slightly Included (two grades). Minute inclusions that are also very difficult to detect under 10x magnification by a trained gemologist.
• SI1 – SI2:
  Slightly Included (two grades). Minute inclusions more easily detected under 10x magnification.
• I1 – I2 – I3:
  Included (three grades). Inclusions visible under 10x magnification as well as to the human eye. These diamonds are typically used in ‘cheap’ or ‘bargain’ jewellery.

Pure white is generally defined as the absence of colour and this is what most people look for in a diamond. The clearer the stone, the more light passes through it allowing it to sparkle more.

HRD, GIA and IGI use an internationally accepted system for grading diamonds according to the purity of their colour.

On this scale D is the highest standard for a colourless stone and the scale then travels downwards through the alphabet to take into account stones with faint or light traces of yellow.

• Diamonds that are graded D to F are extremely rare.
• Diamonds graded G to I show almost no colour to an untrained eye.
• Diamonds graded J to L contain faint traces of yellow and so on.
• DEF:Colourless
  GHI: Near Colourless
  JKL: Faint Yellow
  MNO: Very Light Yellow
  PQR: Light Yellow

The word ‘carat’ is taken from the carob seeds that were used to balance scales in ancient times, but it is not to be confused with the word ‘karat’, which is the method for determining the purity of gold.

Carat refers to the unit of weight by which a diamond is measured, and because larger diamonds are rarer than their smaller counterparts, the cost of a diamond will usually rise in exponential increments according to its size.

As pointed out previously however, there is far more to valuing a diamond than simply measuring its weight. If the other attributes of Cut, Clarity and Colour are of insufficient quality then the weight of a diamond can in theory be virtually meaningless.

It is the combination of these characteristics that determines the individual value of every stone, which is why an authentic HRD or GIA certificate is so essential to your purchasing consideration.