The largest diamond ever found was a carbonado from Brazil; named Sergio, the stone weighed 3,167 carats. (One carat equals one-fifth of a gram.) The origins of carbonados have long baffled ...

Also known as a carbonado diamond, it is possible the black diamond came from outer space. Carbonados of this structure have only been found in Brazil and the Central African Republic, and ...

a jewelry specialist at Sotheby's in London, said in a statement. Black diamonds, or Carbonado diamonds, go back 2.6 billion to 3.8 billion years and some experts believe they may have been ...

The gem is a carbonado, one of the toughest forms of natural diamond. Black diamonds are usually about 2.6 to 3.2 billion years old - a time before dinosaurs existed. The Earth itself is around 4. ...