A month after setting a world record for the most valuable white diamond sold at auction—a 118.28-carat D-flawless that sold for $30.6 million on October 7 in Hong Kong—Sotheby’s Geneva expects to set another record on November 13, when the Pink Star crosses the auction block. The 59.6-carat internally flawless vivid-pink diamond is expected to fetch more than $60 million. It is the largest stone of this color and clarity ever graded by the Gemological Institute of America, according to Tom Moses, the institut…