By Katie McMath
Did you know that diamonds occur naturally in a rainbow of colors? White diamonds are the best known, as they are more common than their colorful siblings. The Gemological Institute of America estimates that only 1 in 10,000 diamonds has enough tint to be considered colored. These special stones are gaining more attention in recent years as collectors and shoppers learn more about them.
Mines like Argyle in Australia harvest and sell incredible gems in all shades. This mine in particular is known for red and pink diamonds, the rarest of all colored diamonds. Most red diamonds are small, but that doesn’t make them less valuable or beautiful. Other factors like vividness, cut, and clarity come into play. So how do red diamonds form? Their color comes not from additional minerals, but their unusual atomic structure which reflects back red light rather than white.
The Argyle mine is also responsible for the popularity of brown diamonds in the 1990s, likening them to champagne and cognac. Before this, they were little known. Today their rich, powerful tones are highly coveted. Jewelry brand LeVian has trademarked the term “chocolate diamond,” advertising them with luscious confectionary metaphors.
In general, brown diamonds with green hues are prized above those with orange. However, with so much natural variety, there is room for each person to pick their favorite. If you don’t mind small sizes,naturally colored diamonds in brown, yellow, and black are within reach.
Yellow diamonds also have an enticing nickname which has elevated their glamorous reputation. When they are pure yellow, with no tints of other colors, they are called canary diamonds. One of the most famous colored diamonds is a canary yellow diamond found in 1877, long before colored diamonds became popular.
The Tiffany Yellow Diamond is a massive stone just under 300 carats. Once Tiffany bought the stone, they trusted its cutting to new gemologist George Frederick Kunz, only twenty three years old at the time. He proved his talent by cutting 90 beautiful facets in a modified square brilliant cut. Audrey Hepburn wore this incredible gem on a collar as she promoted Breakfast at Tiffany’s. At the 2019 Oscars, Lady Gaga wore the historical diamond in a new setting as a pendant.
A large number of all diamonds have yellow or brown tints. In the past they have been color corrected in the hopes of being sold as white diamonds. Ironically, white diamonds are more valuable the closer they are to colorless. Colored diamonds are valued for their intensity and saturation. Today the GIA grades colored diamonds from Faint to Fancy Deep, with Fancy Intense and Fancy Vivid being the most valuable.
Unlike brown and red diamonds which get their color from the arrangement of their atoms (also known as the stone’s “crystal lattice,”) yellow and orange diamonds are colored by nitrogen. Orange diamonds are more rare and desirable than yellow. One of the largest and most colorful orange diamonds was bought by American jeweler Harry Winston the day before Halloween. It was amusingly nicknamed the Pumpkin Diamond.
Two of the most famous colored diamonds come in cooler shades. Also once owned by Harry Winston, The Dresden Green comes from Southern India and dates back to at least the early 1700s. It was bought by the King of Poland and Prince of German Saxony, who stored it in his museum collection in the Dresden palace. This famous collection of artifacts and natural wonders is called the Green Vaults. Its walls, like the Dresden diamond, were once a lovely green color.
The Dresden Green is a pear-shaped stone, weighing about 40 carats. It is a beautiful apple colored green, especially spectacular as green diamonds are very rare. An average of less than ten are sold each year. This means less green diamonds have been studied. Still cloaked in mystery, the green diamond’s makeup is uncertain to gemologists.
It is possible their color comes from radiation in rocks nearby, as the diamond forms. Irradiation is used in labs to make artificially colored green diamonds, usually a deeper color than natural ones, and more consistent in shade throughout. When natural green diamonds are cut, they lose some of their vibrancy, which seems to concentrate on the gem’s outermost layer.
Another unusual phenomenon, some green diamonds change to yellow depending on light and heat. These mystifying gems are called Chameleon Diamonds. Even less is known about them, having just been discovered in 1943. Storing them in the dark, or heating them to about 400 degrees, will change their color temporarily. In a way, they are similar to Alexandrite, the color changing birth stone of June which you can read about on Eve’s blog.
Probably the most famous colored diamond of all is the coveted Hope Diamond. This steely blue gem, known in French as “The King’s Jewel,” was once owned by French royalty. It was made even more famous by its theft two hundred years ago. Today it rests safely in the Smithsonian Institution in Washington DC. In 2000, the Dresden Green and the Hope Diamond were displayed there side by side as two of the most striking and historically rich colored gems.
While the Hope Diamond and the Dresden Green were mined in India, many other blue diamonds come from South Africa. This is a popular location for sourcing yellow diamonds as well. Natural blue diamonds have the unique property of conducting electricity. The reasoning behind this is still unclear, but most likely has to do with the stone’s structure.
Colored diamonds contain a wealth of information, which we have so far only been able to glimpse. Like all diamonds, they come from deep within the Earth, and carry stories upward from this place no human eyes have seen. Colored diamonds are beautiful natural wonders, economic heavyweights, and scientific contributors.
It’s likely that colored diamonds will continue to grow in popularity over the years, as they branch out of obscurity, and are picked up by clever marketers and celebrities. Their abundant, complex range of shades is a reminder of nature’s incredible capacity for surprise. Which color is your favorite?