Image of the Hope Diamond, courtesy the Smithsonian National Museum of Natural History. Get those credit cards ready, home shoppers. Among the samurai swords, creepy dolls, and faint-inducing children’s DVDs, you may soon be able to purchase your very own Hope Diamond replica. The Smithsonian Institution announced yesterday that they’ve struck a deal with home shopping network QVC to market a jewelry line based on the museum’s National Gem and Mineral Collection, part of…