Unlike other fancy colored diamonds, which take on special hues due to exposure to chemicals during the formation process, a pink diamond’s color is usually the result of plastic deformation – a structural change in the diamond crystal that alters the way the stone reflects light, giving it a pink or red shade.
The Argyle Mine in Western Australia is the source of some 90% of the world’s red and pink diamonds, most of them small – the average Argyle pink diamond weighs 1 carat, and the mine yields approximately 50 carats of pink diamonds annually – accounting for 0.0001% of its total diamond production.
The rarity of the mine’s pink diamonds makes them highly sought after, and Argyle holds an annual tender for its pink stones.
While the Argyle Mine is the main producer of pink diamonds, the largest pink stones known today – which include some of the most famous diamonds in the world – all originated elsewhere.
The largest pink diamond in existence, the Darya-i-Noor (186 carats); the Nur-el-Ain (60 carats); and the 56.71-carat Shah Jahaan pink diamond were all discovered centuries ago at the Kollur Mines near Golconda in southern India.
The Agra diamond, a 32.34-carat Fancy Light Pink stone, was also originally mined in India, but pre-dates the Kollur mines. The 59.60-carat Steinmetz Pink, whose color is designated Fancy Vivid Pink, was mined in South Africa and made its debut as a cut and polished diamond only in 2003.
The end of 2010 showed signs that the global diamond industry was climbing out of the financial crisis, and a number of pink diamonds fetched astronomical prices at auctions. An anonymous buyer secured the 14.23-carat Perfect Pink for $23 million at a Christie’s auction in Hong Kong, a per-carat price of over $1.6 million.
And renowned jeweler Lawrence Graff – who also owns the 22.84-carat Graff Pink Orchid – paid $45.6 million for a 24.72-carat Fancy Intense Pink diamond now known as the Graff Pink.