Rare Stamp Sells For $9.5 Million at Auction Listen Download Embed Share Share this on Facebook (Opens in a new window) Share this on Twitter (Opens in a new window) Share this via Email British Guiana One-Cent Magenta, described as the most famous stamp in the world, on display in a glass case at Sotheby's June 17, 2014 in New York. ( STAN HONDA/AFP / Getty ) Produced by Ellen Frankman Produced by PRI and WNYC