Sotheby’s Geneva sale of Gems and Jewelry is scheduled for Nov. 17th. with many colored diamonds on the block feeding a trend that has kept the diamond market stoked through the recession. Nat’l Jeweler has the details:

Approximately 400 lots are set for the auction block and are estimated to fetch more than $29.5 million. […] Among the most anticipated of pieces up for auction is a pear-shaped fancy vivid-blue diamond with a modified brilliant cut and weighing 5.96 carats. It is estimated to fetch between $5.5 million and $7.5 million, and follows up the sale of the “Star of Josephine.” The latter, a cushion-shaped fancy vivid-blue diamond, sold at Sotheby’s Geneva’s May 2009 auction for $9,488,754, or about $1.35 million per carat–the current world auction record price per carat for a blue diamond and any gemstone.

A rare cushion-shaped vivid-green diamond with a modified brilliant cut and weighing 2.52 carats represents the largest vivid-green diamond ever to appear at auction, Sotheby’s said in a media release. It is estimated between $3.1 million and $5.1 million.

Rare Colored Diamonds to Hit Sotheby’s Block (Nat’l Jeweler’s Network)