The biggest ever diamond has been found floating in space. The gem, estimated at close to 10 billion trillion trillion carats, is at the core of a dead star (BPM 37093) - a crystallised white dwarf. The newly-discovered diamond in the sky is a whopping great chunk of crystallised carbon 50 light-years from the Earth in the constellation Centaurus. It is 2,500 miles across (the moon is approximately 2,200 miles across) and weighs 5 million trillion trillion pounds. It has been dubbed "Lucy" in reference to the Beatles' song, "Lucy in the Sky with Diamonds". Diamond specialists told the research...