Blue Nile (NILE), the leading diamond jewelry marketer on the Net, helped him bone up on such factors as color, cut, clarity, and carat???the famous Four Cs" Read more Internet jewellers: A boy's best friend March 19, 2008 'MEN are intimidated when they go into a jewellery store to buy their first diamond,' says Diane Irvine, the chief executive of Blue Nile.