De Beers Millennium Collection blue diamond is auctioned

Blue diamonds are among the rarest of all gems and owe their natural blue color to the presence of the chemical element boron during the stones formation. This  flawless pear-shaped blue diamond that was once part of the legendary De Beers Millennium Collection, is now sold for $6.4 million at auction in Hong Kong to London-based gem merchant Alisa Moussaieff.This internally flawless Fancy Vivid 5.16 ct blue diamond is one of twelve gems from The DeBeers exclusive millennium collection that took decades to assemble. This stone is the first diamond of its kind to appear at an auction from the collection that De Beers presented in 2000 to celebrate the millennium.