Central Michigan University geology professor Mona Sirbescu gets asked all the time if rocks people possess are meteorites, valuable rocks from space. "For 18 years, the answer has been categorically 'no'... But this latest rock was the real thing..." "I could tell right away that this was something special," she said of the 22-plus pound meteorite, described as the sixth-largest recorded find in Michigan and worth potentially $100,000. "It's the most valuable specimen I have ever held in my life, monetarily and scientifically," she added. David Mazurek says he took his doorstop to the university for examination in January, after...