Looks like the University of Arizona has lost itself one pricey rock: The school reports that a 3-inch, half-pound hunk of gold worth $30,000 has been stolen from its Mineral Museum. The rock went missing Friday from an office where it was stored. As the LA Times reports, current gold futures would make the rock worth about $8,700, but the university says that the higher value comes from its "unique, aesthetic, and natural form." The nugget "is the most photographed specimen in the museum's collection because people like to have their picture taken while holding it," says a statement from the school. The unprocessed rock was used frequently in educational seminars.