Chris Portway, age 10, of Anaheim, California, for his question:

Which is the world's biggest diamond?

A diamond taken from the ground looks like a lumpy stone and even the biggest and best ones may be covered with dull, frosty looking coats. The biggest one ever found was named the Cullinan Diamond. It weighed 3,106 carats  which is equal to one pound plus a little more than five ounces. The great gem was a lumpy stone with several flat sides and it looked like a glassy stone coated with white frost.... The diamond was named Cullinan, after the mine's owner Sir Thomas Cullinan. ...

Natural diamonds are cut by experts to show their glittering sparkles. The Cullinan was found in the mines of South Africa and purchased by the government of Transvaal. It was presented to King Edward VII of England and cut by the diamond experts of Amsterdam. It was divided into nine huge brilliants, and 96 smaller diamond jewels were trimmed from the pieces. When the Cullinan was found in 1905, it was three times bigger than any diamond found before. And no bigger diamond has been taken from the earth since.