Colour is the third of our five factors, which, together with the quality of the cut and the clarity, determine the value of a diamond. The best colour for a diamond is no colour at all and, to the untrained eye, most diamonds look colourless.
As with clarity, the colour of a diamond is judged using two main scales – CIBJO is the European system and GIA the American. The more universal GIA scale lists the top colour as “D” with the other colours denoted by descending letters of the alphabet.
The judgement of diamond colours, though subjective, is based on comparison with a “Master Set” of stones. Each master set is graded and matched to one of the internationally agreed standard and as each of the grades has a range it is important to know where the stones in each set sits on that scale. (See below) The asterisks * denote each stone’s position within the grade.
The colours shown on these grading illustrations have been exaggerated. In reality, diamonds of H colour and above can only be defined by an expert, who must compare them with a master set.
Whilst the majority of diamonds are colourless,
natural diamonds can be found in almost any colour,
with pinks, yellows and black being quite widely used
in jewellery making. Some colours, such as a natural
deep red, are very rare and can command huge
prices.
The discovery of diamonds in Australia in the 1970’s
brought to the market a number of strong colours,
particularly bright yellow and a deep brown, which is
called “Champagne”.
Pink diamonds also from the Argyle mine in Australia fetch
a premium and are very attractive.
Very intensely blue diamonds are also found, but again
are rare.
In the case of these “Fancy Colour” diamonds, it is the
intensity of the colour that sets the value.