14. Diamonds are found all over the Galaxy 

Diamond, one of the hardest and most lustrous materials on Earth, is formed under extreme pressure and heat deep beneath the surface of the planet. But it turns out that diamonds are not exclusive to our own planet and may be found throughout the Solar System, Galaxy and beyond. 

Scientists have proposed that diamonds may be formed in the atmospheres of both Uranus and Neptune. Astronomers have discovered the presence of hydrocarbons in both atmospheres and, under the right conditions, they become the building blocks of diamonds. 

In recent years, astronomers have identified a number of potentially diamond-rich exoplanet candidates – worlds orbiting stars other than the Sun. One diamond-rich candidate is BPM 37093, located about 53 light-years from Earth. It is a white dwarf star, once somewhat similar to the Sun, and has since matured into a much smaller, carbon- and oxygen-rich star. Its brightness varies with a pulsating pattern and astronomers were able to use this characteristic to measure how much of the star’s interior has crystalised as the star has cooled. The calculations indicate that as much as 90 per cent of the star’s mass is now a crystal structure – a solid core made of diamond, measuring about 2,000 miles across.  

Nicknamed Lucy (after the Beatles song ‘Lucy In The Sky With Diamonds’) this star may well be hiding the most valuable diamond yet known, comparable in size to the Moon and 100,000 times heavier than the Earth! 

Image: Wanderer in Patagonia by Yuri Zvezdny, National Maritime Museum, Greenwich, London. Courtesy of the artist.