(IDEX Online) - A buyer paid $2.7m, the highest price ever for a diamond auctioned online.The 50.03-ct G-color, VVS2-clarity round gem, with excellent cut, polish and symmetry, was sold by Sotheby's New York without reserve. The estimate was $2.5m to $5m. Eleven individual bidders from seven countries battled it out for what the auction house says was only the fifth round +50-ct diamond to be offered in the past 15 years. Quig Bruning, head of Sotheby's jewelry department in New York said the sale "sends a powerful and positive message that online sales represent a key part of our worldwide strategy and the white diamond market is robust."Two views of the diamond, courtesy Sotheby's