A diamond brooch lost by French emperor Napoleon during the Battle of Waterloo sold for over 3.5 million Swiss francs at a Geneva auction.The piece features an oval diamond weighing over 13 carats and was previously part of Napoleon's belongings abandoned during his retreat.Sotheby’s noted that a separate green beryl worn by Napoleon at his coronation also sold for 838,000 francs, linking increased interest in Napoleonic jewelry to recent thefts from the Louvre museum.