There are two main causes of natural color in diamonds: the presence of elements normally foreign to the diamond, like nitrogen or boron, and imperfections in the gem’s atomic crystal structure. The foreign elements and imperfections can act as color centers – which means they absorb certain hues from the light and reflect others back as the colors we see. The more color centers a diamond has, the more intense its color will be. Click on the following colors to find out what causes them to appear in the natural color diamond:

Yellow

The most abundant impurity found in a diamond is nitrogen. Nitrogen can be found in single, double, triple or quadruple atom arrangements. Only single and triple atom arrangements of nitrogen create color centers that cause the diamond to be yellow. The single nitrogen atom color centers usually result in more intense yellows or ‘Canaries’ as we call them in the trade – and they are very rare. The triple nitrogen atom color center results in lighter yellows or ‘Capes,’ large quantities of which were first found in Cape Province in South Africa. Usually most of the yellow diamonds will be seen with underlying hues of brown, green or orange.

Pink & Red

These are by far the rarest colors seen in a diamond. They occur when the diamonds become subjected to high temperatures and stress during the formation process below the earth. This process displaces many of the carbon atoms from their normal positions, resulting in an imperfect crystal lattice that create red or pink colors. The color in the diamond is concentrated in graining. The more graining inside a stone, the deeper its color. The underlying hues that can be found are either purple or brown.

Green

A certified natural fancy green is the second rarest natural color in a diamond after red. Most green diamonds owe their color to natural irradiation, probably from being created in the Earth in close proximity to radioactive minerals, such as uranium and thorium. The color is usually skin deep, and that’s why a large number of roughs that were graded green usually lose their color during the cutting process. It is very difficult to determine whether the color is natural or enhanced as both are caused by irradiation. One has to look for brown or green irradiation stains on the surface to determine if it is a natural body color. Green can be seen mixed with underlying hues of brown, yellow and more rarely with blue.

Blue

This color is caused by the presence of boron atoms in the diamond. The more boron, the deeper the color. Natural blue diamonds are also semiconductors of electricity. But recently it became known that some diamonds can also become blue as a result of natural irradiation, and these diamonds are usually nonconductive. Also certain diamonds from Argyle were found to be blue due to the presence of hydrogen rather than boron and were again nonconductive. Most of the blue diamonds show a hint of gray or sometimes green.

Black

Black diamonds have often been referred to as gunmetal, jet black, charcoal, and onyx. The color results when all visible light is absorbed by the stone. This happens because of changes in the crystal structure or due to the presence of graphite. There are two types of black diamonds. The Carbonados are heavily fractured with inclusions and are usually considered industrial quality bort. Pure blacks are the rarer form of black diamonds and are caused by the presence of graphite. These are usually the better looking black diamonds.

A few natural color diamonds have become some of the world’s best-known precious stones. Find out more about these amazing jewels by clicking on it

The Hope Diamond

Of all the blue diamonds in the world, this 44.52-carat antique-cut cushion-shaped stone is probably the most famous – or infamous, since it seems to have brought a curse on anyone in its possession.

As the story goes, Hope Diamond was originally the 110-carat blue diamond sold to King Louis XIV of France in 1668. It was named the French Blue and passed on to Louis’s descendents as part of the crown jewels. One of them, King Louis the XVI was executed along with his wife, Marie Antoinette, during the French Revolution in 1793. The French Blue was placed in a museum, but promptly stolen, along with the other crown jewels, during the upheavals. One suggestion was that it was then recut, soon to reemerge as the Hope Diamond.

It got its name when in the 1830s it came into possession of a banker named Henry Philip Hope. It stayed in the Hope family until a descendant Lord Francis Hope frittered away his fortunes through gambling and was forced to sell the diamond. The stone changed hands many times, seeming to bring nothing but misfortune to any of its subsequent owners. Cartier sold it to an American Mrs. Edward McLean of Washington for US$180,000. Tragedy befell her when she lost her only child in an accident, and then her fortune, finally committing suicide. The diamond was donated by Harry Winston to Washington’s Smithsonian Institute, where it’s been on display ever since. The misnamed Hope Diamond is one of the most popular exhibits at the Smithsonian, probably seen by more people each year than any other diamond.

The Black Orloff

The brilliant 67.5-carat cushion-shaped Black Orloff is the most famous black diamond in the world. It is also called the ‘Eye of Brahma,’ as it originated in India. After its discovery it was stolen by a monk before turning up in the hands of the Russian Princess Nadia Vyegin-Orloff. In 1969 R. Charles Winston of New York sold it for US$300,000. It was again resold at Sotheby’s in 1990 for just US$90,000. But the stone reached its epitome of glory in 1995 when it was sold for US$1.5 million.

The Dresden Green

The apple green color of the 40.7-carat pear-shaped Dresden Green makes it one of the rarest diamonds in the world. It’s named after the capital of Saxony, Germany, where it has been on display for over 200 years. The diamond was bought from the Golconda mines in India in early 18th century. It was later sold to Friedrich Augustus II of Saxony and put on display in the Green Vaults (the name is incidental) under the Dresden castle with other prized possessions. It was part of a number of different settings and now prevails in the form of the bottom part of a hat ornament. During the two world wars the contents of the Green Vaults were often moved to the safety of the Konigstein fortress. At the end of World War II the Russians took the diamond to Moscow, but in 1958 they returned it to Dresden, where it was again put on display at the Green Vaults.

The Golden Jubilee

In 1986 a 755.5-carat golden yellow rough diamond was found in the Premier Mine of South Africa. Four years later, it was polished into a beautiful cushion-shaped golden yellow diamond of 545.65 carats – thus becoming the largest polished diamond ever. In 2000 it was presented to Thailand’s King Bhumibol Adulyadej by a group of prominent Thai businessman in order to mark the 50 years of the King’s ascent to the throne. The diamond then became known as the Golden Jubilee. It is now on display at the Royal Museum at the Pimammek Golden Temple Throne Hall in Bangkok, Thailand.

The Hancock Red

Red is one of the rarest colors found in a diamond. There are no more than thirty recorded cases of reds of significant size, most of them with underlying brownish hues. That’s what makes the 0.95-carat brilliant-cut purplish red Hancock Red stand out as such a rarity. The diamond got its name from Warren Hancock, an owner of an oil company in Montana. His jeweler Arnold Baron sold Mr. Hancock the red with a smaller pink for a total of US$13,500.

Mr. Baron admitted that he lost a few nights’ sleep worrying if the price was a bit too high for such a small diamond. Little did he know that a few years later the same stone would sell for the highest per-carat price ever paid for any gemstone. This happened on April 28, 1987 when it was bought at a Christie’s auction for an amazing US$880,000 (US$926,316 per carat). It is rumored that the buyer was acting on behalf of the Sultan of Brunei, an avid collector of COLORed DIAMONDS.