Every woman dreams of receiving a huge, sparkling and priceless diamond. Now scientists have discovered the largest diamond in the universe.

But it's well beyond the reach of the most lovestruck men - 50 light years to be precise. Space scientists revealed that they had discovered a ten billion trillion trillion carat gem. Measuring 2,500 miles across and weighing five million trillion trillion pounds, the rock was found on Valentine's Day buried in the core of a white dwarf star in the constellation Centaurus.

"It's the mother of all diamonds," said Travis Metcalfe, who led the team of researchers at the Harvard-Smithsonian Centre for Astrophysics in America.

"You would need a jeweller's loupe the size of the Sun to grade this diamond." Named Lucy, after the Beatles' song Lucy in the Sky with Diamonds, the rock has sent a ripple of excitement through the scientific world.

The largest diamond found on earth was the 3,106-carat Cullinan. It was cut into nine major stones, including the 530-carat Star of Africa, now a part of the Crown Jewels. Diamonds were first discovered in India more than 2,800 years ago. The Ancient Romans believed that the stones were splinters of stars that had tumbled to earth.

In Ancient Egypt, diamonds were symbols of eternity and were used in funeral rites. In the Middle Ages, men wore them to symbolise their courage and virility. The tradition of giving them as love tokens dates from 1477, when Archduke Maximilian of Austria gave a diamond ring to Mary of Burgundy.

(Agencies)