Call +852 2711 6699
YOU ARE HERE:   Home > All ABOUT DIAMONDS > THE 4Cs > Colour

All About Diamonds

All you need to know about
diamonds before deciding
which to buy.


Diamonds used in jewelry are broadly of two kinds: white or fancy coloured.

White or colourless diamonds are graded according to subtle variations in colour denoted by slight brown or yellow tinges. The GIA uses a scale from D to Z to grade white diamonds, where D to J is considered near-colourless. Small variations on this scale may have disproportionate influence on value.

Good Diamonds Have No Colour

For white diamonds, the GIA D-Z colour grading scale describes the normal range of colour, where D is colourless and Z denotes light yellow or brown.

Naturally, colourless diamonds in this range are more valuable (higher price per carat) as they are very rare. Small differences in colour may result in dramatic differences in price.

Colour is more visible in larger than in smaller diamonds.

The colour of the mounting (ring, ear-ring or other ornament) also has an impact; for instance, a G, H, or I colour diamond may look colourless when mounted on an 18K white gold ring.

However, any attempt to value a diamond must necessarily take into account other factors such as weight, clarity and cut.

How Are Diamonds

Diamonds are colour-graded by expert graders by comparing them to a set of master stones in controlled conditions, or a master set of diamonds that represent the colours from D to Z.

How Does Fluorescence Affect
Diamond Colour?

Fluorescence in diamonds is a measure of the emission of visible light when exposed to ultra-violet radiation. Fluorescence is visible in about 35% of gem-quality diamonds. Fluorescent colours include blue (the most common), white, yellow and orange.

Fluorescence is not necessarily a negative characteristic; for example, a light yellow diamond may look colourless in sunlight due to the presence of strong blue fluorescence. However, in diamonds approaching colourless, strong fluorescence may result in the diamond looking cloudy or "oily", thereby lowering
its value. Hattons only carries diamonds with fluorescence graded from None to Medium.