Diamonds might be forever but that doesn’t stop them being bought and sold. One stone thought to have once belonged to Marie Antoinette, the last queen of France, has just sold for US$14 million (£10 million) at an auction in New York – about three times the asking price. Set into a platinum ring and weighing a total of 15.5 grams, the clue to the diamond’s uniqueness is in its name: the Marie-Thérèse pink.
This 10.38 carat pink diamond has been changing hands for generations, and previously sold at an auction in Geneva for an unknown amount in 1996. Pink diamonds are very rare and there are many things that scientists still don’t know about them.
Diamonds are generally formed under intense heat and pressure deep within the Earth’s mantle, roughly 150–200 kilometres below the surface. Most natural diamonds crystallise over billions of years, composed almost entirely of carbon atoms arranged in a tightly packed, cube-like structure.
