NEED TO KNOW: DIAMOND COLOUR
Rather than the rainbow spectrum of colours that make up the brilliance, fire and scintillation of a diamond, the ‘colour’ that is referred to in the Four Cs is the natural presence (or lack) of subtle yellow, brown or grey hues that appear within a diamond’s intrinsic form. Colour here does also not refer to pink, green, blue and other naturally-coloured diamonds.
Colour enters diamonds when they are first formed. The rough stones take shape under intense pressure and temperature, deep down in the earth’s mantle, before being forced upwards towards ground level by deep-seated volcanic eruptions. When the diamonds are forming, elemental traces can impart tints of colour. Nitrogen creates the yellowy brown colours that impact white diamonds. However, some diamonds are formed in circumstances that allow for little if any colour to appear – these are the rarest and most valuable diamonds.
Diamonds receive natural light, which is broken up into spectral colours withintheir body before being passed back to the eye, much like a prism. Diamonds that are murky or coloured lessen this effect. Colourless diamonds, on the other hand, are able to receive and expel more light, both as white light and coloured light (brilliance and fire), and as such appear more vibrant and sparkling.
International Diamond Colour Scale
The colour of a diamond is graded using letters, starting with D and continuing right the way down to Z.
Stones that are classified as D are completely clear and colourless, and these stones are very rare. As the letters progress, very slight traces of colour give way to more noticeable hues. Generally, diamonds in the D–F categories are considered colourless, those that fall into the G–F band are close to colourless, and the final group, from K–Z have clear colour attributes.
At Queensmith, we generally stock diamonds from D-H. As a diamond’s setting and the surroundings in which it is viewed can affect the appearance of colour, we will always show you our stones in a neutral environment and will happily exhibit them under natural light, too.