Natural blue diamonds are rare and truly one-of-a-kind as only a few are discovered every year. The coveted blue colour is created by trace amounts of boron dispersed through a diamond’s crystal lattice. Carbon atoms are replaced by boron atoms during the formation. Smaller than carbon, each boron atom distorts the lattice structure so only blue wavelengths pass through the diamond. Usually seen as bands, the more boron within the diamond, the deeper the blue colour so essentially, no two blue diamonds are the same.
Rarity of Natural Blue Diamonds
In The Fancy Colour Diamond Book by Eden Rachminov, the author explains that less than 10% of coloured diamonds are classified as Type IIb diamonds. Type IIb diamonds contain trace amounts of boron and almost no nitrogen in its composition. Nitrogen caught in the crystal lattice of the diamond absorbs blue wavelengths affecting the saturation of blue and can cause a secondary yellow hue. The more intense and ‘pure’ the blue, the higher the value placed on the diamond.
Not all blue diamonds are Type IIb, some fall into the Type Ia classification such as those found in Australia’s Argyle mine in the Kimberley region of Western Australia. Where boron is responsible for causing the blue colour in Type IIb gems, hydrogen bonding to the carbon atoms create the blues, violets and greys of the exceptionally rare Argyle blue diamonds.
Another interesting fact is that natural blue diamonds are not even-toned throughout. There can be parts of the diamond that are more saturated than others. Thus, it is difficult not only to acquire these diamonds but also to cut the shape to ensure that the value of each diamond is maintained.
Additionally, natural blue diamonds pique the interest of not only collectors and enthusiasts but scientists as well. According to research, among all the diamonds, blue diamonds are the best conductors of heat and electricity. However, due to their rarity and value, there is very little research on their unique properties.
History of Natural Blue Diamonds
Diamonds take millions of years to form, maybe even billions of years, through the compounding of carbon and other elements. What makes blue diamonds unique in this process is that blue diamonds do not merely form below the earth’s surface.
Research shows that unlike diamonds that form within the earth’s mantle at around 100 to 150kms, natural blue diamonds form at depths of 410 to 660kms, with materials that are in the oceanic crust. That means that blue diamonds are formed even deeper within the earth’s mantle and that the boron which forms part of the diamond may have been once part of an ancient ocean.
It explains why natural blue diamonds can only be found in a few mines. The most well-known are the Cullinan mine of South Africa, the Indian mines in Telangana and Andhra Pradesh, the Aredor mine of Guinea, and the Argyle mine in Australia.
While blue diamonds are unique, scientists have been able to develop synthetic blue diamonds which are engineered to show a bluish hue. The fact that their colour may be manufactured, however, does not decrease the value of true natural blue diamonds.
Famous Natural Blue Diamonds
Because there is less than 5% of natural blue diamonds in the market, a few can be very memorable. Here are some of the most popular natural blue diamonds:
1. The Hope Diamond
It is no doubt that the Hope Diamond is the most famous blue diamond, if not the most famous diamond in the whole world. While it is unclear where the diamond was mined, it is believed to have been found in the Kollure mine in India.
The Hope Diamond is most well-known because of the popular belief that it is cursed. Anyone well known who has owned it or possessed it has had terrible luck. Louis XIV was beheaded, while King George IV fell into debt. Contrary to this belief, however, the notion that it is cursed was only sensationalised by the media in the late 1800s to sell newspapers. There is, in fact, no truth to it.
Currently, the Hope Diamond has a home in the Smithsonian Museum. She has only left the museum four times since 1958.
This natural blue diamond was found in the Kollure Mines of India in the 1600s. The diamond had a greyish-blue tone with wonderful clarity. It was acquired by King Philip IV and he eventually gave it to his daughter in 1664.
In 1931, it was put up for sale in an auction but did not meet the intended sale price. It’s ownership and whereabouts remained unknown until 2008, when a diamond dealer named Laurence Gaff purchased it for $23.4 million.
A lot of controversy over the gem came about when Graff had the diamond recut and renamed from Wittelsbach to Wittelsbach – Graff. Diamond enthusiasts considered this a reckless way of increasing the value of the diamond.
Graff’s decision to cut off 4.45 carats of the weight was later found to be life-changing. Its greyish colour changed to a deep blue, the clarity grade changed from VS2 to eternally flawless, the scratches and abrasions disappeared, and most importantly, the gem almost tripled in value. Eventually, the Wittelsbach – Graff sold for $80 million.
The Blue Moon of Josephine is considered the world’s most expensive diamond. This 26.9-carat rough diamond was found in January 2014 in the Cullinan mines of South Africa, and valued at around $15 to $20 million before polishing. A month later, Petra Diamonds sold the gem in the rough to Cora International for $25.6 million.
In August 2014, Cora International presented the natural blue diamond as a 12.03-carat cushion-cut, flawless, vivid blue diamond with the highest clarity and the highest colour grading. It was later sold for $48.5 million, which makes it the largest cushion-cut blue diamond, and the most expensive one sold per carat.
Investing in Blue Diamonds in Australia
If you are interested in getting yourself a natural blue diamond, now is your chance. The Argyle Diamond Mine in Australia produces pink, red, and of course, blue diamonds. These diamonds are so rare that they are found only once or twice for every 25 million carats of diamonds unearthed. It’s rarity definitely makes it a good investment. Get the best quality for the lowest price with Argyle Diamond Investments.