Diamonds in the normal colour range are colourless to light yellow and are described using the industry’s D-to-Z colour-grading scale. Fancy colour diamonds, on the other hand, are yellow and brown diamonds that exhibit colour beyond the Z range, or diamonds that exhibit any other colour face-up. These rare specimens come in every colour of the spectrum, including, most importantly, blue, green, pink and red.
The coloured diamonds in the Aurora Butterfly of Peace were assembled over a 12-year period by Alan Bronstein and Harry Rodman of Aurora Gems Inc., New York. The butterfly’s 240 stones show nearly the full spectrum of colour and cut styles of naturally coloured diamonds. - Courtesy of Alan Bronstein
Gem diamonds in the D-to-Z range usually decrease in value as the colour becomes more obvious. Just the opposite happens with fancy colour diamonds: Their value generally increases with the strength and purity of the colour. Large, vivid fancy colour diamonds are extremely rare and very valuable. However, many fancy diamond colours are muted rather than pure and strong.
The colours exhibited by natural fancy colour diamonds are usually not very intense. - Courtesy of T. Horovitz
Fancy colour diamonds come in almost any colour you can imagine. Red, green, purple and orange are generally the rarest, followed by pink and blue. Yellows and browns are the most common fancy colours, but they’re generally less valuable than the rarer colours.
The strength and purity of this 0.81-carat diamond’s colour increases its value beyond that of a similar-size diamond in the normal colour range.
Blacks, greys and fancy whites are considered fancies, too. Some have been fashioned into gems. The 67.50-carat Black Orloff diamond, named after the Russian Princess Nadia Vyegin-Orloff, is the most well-known example.
The cushion-cut Black Orloff diamond weighs 67.50 carats and was reportedly cut from 195-carat rough. It’s set in a diamond and platinum necklace.
Fancy white diamonds can have an opalescent look. - Courtesy of collector, Dr Pericles John Lentz
Spectacular prices in high-profile auctions are another factor in the increased awareness of fancy colour diamonds. Not all fancy colour diamonds command such high prices, however. Many people consider yellow and brown fancies less desirable than near-colourless stones of equal weight and clarity. And deeper yellows and browns are generally less valuable than other fancy colours.