If you think diamonds are a girl's best friend, think again. The majority of expensive stones are bought by men, who purchase them for their personal collections. Sothebys D-Grade Flawless Diamond Price: $16 million Carats: 108 This flawless white diamond is arguably the finest of its kind for sale anywhere in the world. What makes it extraordinary isnt so much its heft--a generous 108 carats--as its nearly total absence of flaws. Mouawad Diamond Necklace Price: $12 million Carats: 70 (for the largest stone) This necklace of white and colored diamonds was once displayed at Londons Natural History Museum and is currently owned by the Robert Mouawad as part of his collection housed in Geneva, Switzerland, which contains his higher-end pieces. The largest jewel in the necklace is a 70-carat white sparkler. Leviev Fancy Vivid Yellow Diamond Price: $10 Million Carats: 77.12 Fancy vivid is the highest rating you can give a colored stone, and London jeweler and Israeli diamond tycoon Lev Leviev is offering for sale one of the worlds most spectacular. Leviev, who controls the third largest group of diamond mines in the world, got this stone from one of his own diggings. It hangs from a white diamond necklace. Graff Fancy Vivid Pink Pear Shaped Diamond Price: $10 Million Carats: 13 Graff doesnt loan diamonds to celebrities, but that doesnt mean you cant have your own piece of red carpet bling. Collectors will be clamoring for this beauty, mounted in a platinum ring with white pear-shaped diamonds on both sides. Harry Winston Fancy Intense Pink Diamond with two Trapezoid Diamonds Price: $8.3 Million Carats: 10.11 Pinks are among the rarest of colored diamonds, and this particular stone is one of the largest offered on the market today. The diamond displays a 100% pure pink color that is evenly distributed and saturated to a degree found only in the best vivid-grade diamonds. Clarity rating: VVS1.