FANCY COLOURED DIAMONDS EDUCATION

The creation of a natural colour diamond is nothing short of a miracle. In addition to the extreme conditions that must be present for a diamond to form inside the Earth, minute amounts of trace elements must also interact with the carbon atoms to permanently alter the colour. It is estimated that a diamond has only a 1 in 10,000 chance of possessing any natural colour, regardless of the spectral hue, which makes any fancy coloured diamond a true natural wonder.

Clarity grades can be assigned to fancy coloured diamonds the same way as diamonds in the colourless range, however, clarity is not one of the most important factors in determining the value of natural colour diamond. It is a consideration in the valuation, but not a critical factor. In other words, a natural colour diamond with deeper colour and lower clarity is considered more desirable than one with lighter colour and higher clarity. Often times, the unaided eye cannot detect inclusions in a fancy coloured diamond because these characteristics blend in with the diamond’s colour.

Cut is also not considered a critical factor in valuating a natural colour diamond, since the diamond is typically fashioned to enhance the colour as much as possible while retaining the maximum amount of weight from the rough crystal. This practice lends itself to brilliant cut styles, as opposed to step-faceted, with deeper cut proportions and thicker girdles on finished diamonds. The most common shapes found in large fancy coloured diamonds are radiant cuts and cushion cuts. Though rounds are by far the most popular shape for diamonds in the colourless range, fancy coloured diamonds do not hold colour as well in this shape. Premium-Ideal cut proportions in rounds can improve the “face-up” colour of a diamond in the normal range, but will actually cause the strength of the colour in a fancy coloured diamond to appear weaker due to the way light performs.

Strength of Colour

Diamonds in the colourless (D-Z) range usually decrease in value as the colour becomes more apparent. The opposite is true with fancy-coloured diamonds. In fact, the single most important value factor that affects the rarity of a fancy coloured diamond is colour. Fancy-coloured diamonds are found in nearly every colour of the rainbow. Red, green, purple, and orange are the rarest colours, followed by pink and blue. Yellow and brown are the most common fancy colours; therefore, they are the most affordable. Aside from the spectral hue, the purity and strength of the colour also affect rarity.

Hue refers to the dominant colour of the stone, such as pink, blue, or yellow. There can also be modifiers, or tints, which impart more than one colour to a stone. For instance, a purplish-pink diamond indicates a stone with a principal pink hue and a slight purple tint. If no modifiers or tints exist in a stone, then the hue is said to be pure.

Tone refers to how much lightness or darkness a stone appears to retain. The range of tones goes from light to dark.

Saturation describes the strength or intensity of the hue. The saturation of light diamonds can very from pastel to vivid and intense. Dark diamonds can range from dark to deep.

Fancy Yellow DiamondsLight to vivid yellow diamonds are found in different countries. The saturation of colour is dependent upon the amount of nitrogen present. The largest and most saturated yellows have been discovered primarily in South Africa. These include the largest known yellow diamond, the Red Cross, which weighs 205.07 carats, and features a Maltese Cross visible from the top facet.

Fancy Pink DiamondsPink diamonds come in a variety of colours, including bubblegum and coral. There are also brownish and purplish pink diamonds. The Argyle mine in Australia is the only mine in the world that produces a consistent volume. A whole year of Argyle's intense pink diamond production can be held in the palm of one hand. To put the true rarity of these stones in perspective, of every million carats of rough diamond production at Argyle, only one carat is suitable for sale in its tender.

Fancy Blue DiamondsFancy blues range from very light shades through to a steel blue hue, and derive their colour from boron impurities. Due to the presence of boron, some blue diamonds are able to conduct electricity! The Cullinan mine near Pretoria, South Africa is the world's only notable blue diamond producing mine. The Hope Diamond, arguably the most famous diamond in the world, is a natural fancy blue, weighing 45 carats. This deep blue diamond is now at the Smithsonian Institute in Washington DC.

Fancy Green DiamondsOnly a handful of green diamonds are introduced into the market each year. Pure green diamonds are valued more than those which are yellowish-green or grey-green. Fancy green diamonds are sourced from South Africa and other parts of the continent. The green colour comes from being near radioactive sources during formation. This process takes at least a million years to occur, hence their rarity! The most famous green diamond is the 41 carat Dresden Green Diamond, currently housed at the Staatliche Kunstsammlungen in Dresden.