Nothing’s recession-proof these days, but diamonds are having are having an especially rough go in the markets. New York’s famed diamond district is now plagued with empty booths and “for rent” signs and sales are down a whopping 50 percent in the past year. “The number of jewelry company bankruptcies has doubled nationwide in the past year…and the Northeast saw a 33 percent decline in jewelry retail,” reports Crain’s. Not all the sparkle has faded away, however, as a rare blue diamond is expected to ring up $8.5 million at auction next month. Sotheby’s is banking on the cushion-shaped, 7-carat gem, which was found in a South African mine, to bolster their numbers for the year. Who will be the lucky bidder?