Confirming what the Beatles always knew, astronomers have actually found a diamond in the sky - directly above Australia. It is the biggest known diamond in the universe, in fact.

According to American astronomers at the Harvard-Smithsonian Centre for Astrophysics, a white dwarf star in the constellation of Centaurus, next to the Southern Cross, has been found to have a 3000-kilometre-wide core of crystallised carbon, or diamond.

It weighs 2.27 thousand trillion trillion tonnes - that's 10 billion trillion trillion carats, or a 1 followed by 34 zeroes. The biggest earthly jewel is one of the British crown jewels, the 530-carat Star of Africa.