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At Hard Carbon Inc. we are experts in fancy colored diamonds and serve a broad clientele from around the globe and across North America. One of the most rare and valuable diamonds we love to source for clients is the pink diamond. The highest quality of pink diamonds can fetch millions of dollars at auction and well surpass other fancy colored diamonds and ‘clear’ diamonds in value. The pink diamond has always been a mysterious gem as scientists grappled with the reason behind its pink hue. Unlike other fancy colored diamonds which have trace elements which alter their color, the pink diamond has no trace elements. Now, scientists have found the reason for this glorious color!
An important element to the uncovering of this mystery involves the Argyle mine in Western Australia. This mine closed in 2020 after operating for nearly 37 years after bringing the world an abundance of pink diamonds; it is estimated that nearly 900 million carats of pink diamonds were mined during its operation. The Argyle mine, operated by Rio Tinto, ended up supplying the world with approximately 90% of pink diamonds. By 2020 Rio Tinto had mined so many diamonds that the mine was completely depleted and had to close. While this had an impact on the pink diamond market, making them even more valuable, this led to a wonderful new discovery.
Since closing the mine, scientists have been studying it to understand why this area of the earth produced pink diamonds in such abundance. In an exciting turn of events, researchers from Curtin University in Perth, Australia, have discovered that the rocks in the Rio Tinto mine are nearly 1.3 billion years old! Using lasers to analyze the rock deposits of the mine scientists realized that this more accurate way of dating the rock put its development at approximately 100 million years older that first understood. This means that the area of the Argyle mine was formed due to the breakup of an ancient supercontinent.
The fortuitous place where the Argyle mine is located was once the location of four proto continents: those of Australia, Antarctica, China, and North America. The name of this proto continent is Nuna. Inevitably the four continents caused thick continental crusts which in turn caused a massive build up of heat deep within the earth. It is thought that between 1.5 to 1.3 billion years ago this super continent broke up and parts of Western Australia (where the Argyle mine is located) were, in essence, stretched. The area in Western Australia created spaces in the Earth’s crust where magma was able to shoot up. The rift caused in this area of Australia is a prime example of how the earth’s mantle is destabilized when supercontinents break apart. With this re-dating of when pink diamonds were created it is thought that the extreme heat and pressure and movement of earth caused the diamonds to float closer to the earth’s crust – they may have surfaced in a matter of days or weeks!
All diamonds form deep within the Earth’s mantle – almost 150 kilometers deep! Diamonds were primarily thought to be brought to the Earth’s surface solely from volcanic eruptions. It is now known that pink diamonds were brought to the surface by a supercontinent breaking apart. This would also explain the pressure the pink diamonds were put under that would cause their crystal lattices to bend – and cause their pink hue.
Pink diamonds have had, in the last decade alone, record breaking results at the auction house. In 2017 Sotheby’s Hong Kong sold a 59.60 carat Fancy Vivid Pink Color and Internal Flawless pink diamond called the Pink Star Diamond for $71.1 million. The following year in 2018 Christie’s sold the 18.96 carat Pink Legacy diamond for $50 million USD, it went for just over $2.6 million per carat. Four years later Sotheby’s Hong Kong sold the infamous Williamson Pink Start diamond for $5.5 million, surpassing the Pink Legacy at just over $5.1 million per carat. The Williamson Pink Star is particularly valuable as is in an Internally Flawless Fancy Vivid Pink.
You can see why this recent discovery excites us at Hard Carbon Inc. Researchers believe that pink diamonds might be found in other areas not purely related to historic volcanic eruptions. Scientists and researchers can now examine areas of the globe where similar super continent breakups took place to see if pink diamond deposits are present. Pink diamonds have always been a mysterious and sought after diamond for both investment purposes and for the creation of some of history’s most priceless and sought after pieces of jewelry.
This news brings hope to many that the mining of pink diamonds is far from over.