1. AuctionsNow this is a piece of history. The Beau Sancy, a 34.98 ct. pear-shape wonder that has been the property of no fewer than four royal families and appeared in two monarchs’ crowns, will go under the hammer at Sotheby’s Geneva on May 15. First ­discovered in the 1500s, the stone was owned by royals in both England and France; at least two French monarchs pawned it to settle debts. For the past 300 years, the legendary gem has belonged to the House of Prussia, which passed it down through four generations—until its current owner, Prince Georg Friedrich, great-great-grandson of the final German kaiser, decided it was time to sell. The stone, which has been shown publicly only four times in the past 50 years, will be ­showcased in an ­international tour before the auction. It is expected to fetch between $2 million and $4 million. 2. GoldiStockphotoWarren Buffett seem