Diamonds come in a variety of colours. The majority of diamonds sold in the jewellery industry range from near colourless to very light yellow or brown. The most valuable are colourless diamonds (which have extraordinary ability to absorb all rays of light equally) and fancy coloured diamonds (due to their rarity and uniqueness). The colour in Natural Fancy coloured Diamonds is present because of presence of certain elements like nitrogen, boron, etc. which were introduced in diamonds by nature during their formation in earth).

 

Yellow Diamonds	Pink Diamonds	Blue Diamonds	Black Diamonds
Champagne Diamonds	Brown Diamonds	Chameleon Diamonds	Grey Diamonds
Green Diamonds	Olive Diamonds	Orange Diamonds	Purple Diamonds
Red Diamonds	Violet Diamonds	White Diamonds

Each coloured diamond is different not only because of its natural body colour but also because of the way it is shaped and finally polished. Most fancy colour diamonds are cut into cushion or radiant shapes forms, which best bring out the depth of hue. The most skilled cutters shorten the optical light path through the diamond, creating the bright sparkle that is reflected from them. Cutting deeper pavilions and creating different facets may intensify colour.

The cutting of coloured diamonds is significantly important, performed by highly skilled craftsmen who combine their technical knowledge with a deep appreciation for beauty and colour. Different regions of the earth have yielded particular types of coloured diamonds, and each colour requires a master cutter's knowledge and appreciation to unlock the beauty within.

Colour is the most important factor in determining the beauty and value of a gemstone. There are four main factors involved in a gemstone's colour: hue, tone, saturation, and distribution.

Hue
is the term used for the actual colour of the spectrum: red, orange, yellow, green, blue, indigo or violet. The more pure a gemstone's hue, the more valuable it is. Because gemstones are composed of many naturally occurring elements, they typically emit one dominant colour and one or more underlying colours.

Tone
represents how light or dark a stone appears depending on how much brown, black, gray or white is present.

Saturation
is the intensity of brightness of the colour. The more colour saturated a gemstone is, the more valuable it becomes.

Distribution
is how evenly the colour spreads out across the body of the gemstone.

RARITY

No other jewel combines the rarity, beauty and sex appeal of a coloured diamond. The majority of white diamonds are not rare. For over 60 years, the DeBeers cartel has convinced Americans that diamonds equate with love and to be treasured. However, coloured diamonds are truly exceedingly rare and are simply geological flukes. For every 100,000 D-flawless diamonds, there is probably one coloured diamond, and it is probably not flawless. The beauty and the rarity of these coloured diamonds have spawned unprecedented desire and unparalleled prices.Red diamonds are undoubtedly the rarest of coloured diamonds. Green and Blue coloured diamonds follow closely behind and are exceptionally rare. Following in rarity are the Purple, Pink and Violet colours. The next layer of rarity goes to orange and olive. Yellow, brown, champagne, gray and black diamonds are only modestly rare.

Before the discovery of the Argyle mine in Western Australia in the mid-1980s, the finest quality pink diamonds found elsewhere were very faintly coloured. Argyle pinks and purple-pinks in contrast, have a characteristic full-bodied, bright and intense colour. "Of every 39.2 million carats of diamonds mined at the Argyle, only 40 carats of pink diamond is deemed worthy of being presented for sale at their annual, invitation-only tenders. This is rarity as defined by Mother Nature.Some of the rarest and most famous coloured diamonds where brought together at the Smithsonian Museum in 2003, being part of an exhibit titled The Splendour of Diamonds (above photo). The exhibit lasted from June 27th to September 30th and featured a number of exceptional coloured diamonds: (top row left to right) the Steinmetz Pink, the Millennium Star, the Allnatt Diamond (bottom row left to right) the Heart of Eternity, the Pumpkin Diamond, the Tiffany Yellow, the Moussaieff Red and the Ocean Dream.

Colour Saturation

Fancy coloured diamonds are graded according the saturation of the colour along with different hues present in them. Following is a sample scale of colour saturation: In Fancy coloured diamonds, main dominant colour is listed after the modifying colours. If a diamond is graded as Fancy Grayish Greenish Yellow then the dominant colour would be yellow with gray and green as modifying colours.One important factor to remember is that in coloured diamonds, clarity is secondary to the intensity of the diamond's colour.